ライフサイエンスコーパス: yeast protein

1 lf the chance that they are related to a non-yeast protein).

2 me (the subcellular distribution of all 6100 yeast proteins).

3 eric or tetrameric coiled-coil domain from a yeast protein.

4 rvation, essentiality, and connectivity of a yeast protein.

5 shows 48% identity and 64% similarity to the yeast protein.

6 that is 29% identical and 47% similar to the yeast protein.

7 ional as well as a structural homolog of the yeast protein.

8 residues, compared with 985 residues in the yeast protein.

9 ations at 35 positions of the 436-amino acid yeast protein.

10 ons (QR) in the in vivo concentration of any yeast protein.

11 functional compatibility between the fly and yeast proteins.

12 ,000 proteotypic peptides for 4,030 distinct yeast proteins.

13 physiologically phosphorylates mammalian and yeast proteins.

14 ese questions in a reconstituted system with yeast proteins.

15 neration of specific antibodies to rFXIII or yeast proteins.

16 what was previously described for homologous yeast proteins.

17 ted information about potential orthologs of yeast proteins.

18 s motif is found in 1,139 of 5,889 predicted yeast proteins.

19 First, we purified Rtf1 and its associated yeast proteins.

20 ermined the subcellular localization of 2744 yeast proteins.

21 unctions with confidence values to these new yeast proteins.

22 lphenols could be limited by the presence of yeast proteins.

23 her Hsl1 or Swe1 in the absence of any other yeast proteins.

24 dentified as describing interactions between yeast proteins.

25 ression and/or function of 18 of the fission yeast proteins.

26 spite low overall sequence similarity to the yeast proteins.

27 tituted Mcm2-7 loading with purified budding yeast proteins.

28 ich collectively modify approximately 50% of yeast proteins.

29 inst autodegradation than both the human and yeast proteins.

30 s related-1 (CAP) domain of pathogen-related yeast protein-1 (Pry1) from Saccharomyces cerevisiae is

31 singly, the level of isoaspartyl residues in yeast proteins (50-300 pmol of isoaspartyl residues/mg o

32 , we demonstrate that 73% of the variance in yeast protein abundance (47% in E. coli) is explained by

33 validated the depletion mechanism with known yeast protein abundances, and we observed greater than t

34 athway are found, but the orthologs of three yeast proteins, accounting for the route from phosphomev

35 o the identification of an orthologue of the yeast protein Ada1 and the novel protein encoded by CG44

36 ed Drosophila melanogaster homologues of the yeast proteins Ada2, Ada3, Spt3, and Tra1 and showed tha

37 haracteristics are similar for the human and yeast proteins, although the details differ and the hTBP

38 loop containing the coordinating His in the yeast protein and the fourth Cys in the bovine protein a

39 e activation of Put3p requires no additional yeast proteins and can occur in the presence of certain

40 f Okazaki fragment processing using purified yeast proteins and model substrates.

41 Because many yeast proteins and pathways are conserved, these results

42 nificant overlaps between stress aggregating yeast proteins and proteins that aggregate during ageing

43 this prediction, we examined the full-length yeast proteins and truncated versions thereof consisting

44 ation from the Protein Data Bank (PDB) about yeast proteins and/or their homologs.

45 nding by Yap8 does not require an additional yeast protein, and Yap8 is regulated neither at the leve

46 f ligand binding sites, interactions between yeast proteins, and functional consequences of human nsS

47 e modification of Rpl3 and potentially other yeast proteins, and now designate it Hpm1 (Histidine pro

48 codon adaptation index value for identified yeast proteins approximates to that predicted for the en

49 with candidate interacting partners for each yeast protein are available at http://www.protsuggest.or

50 Our results indicate that 47% of yeast proteins are cytoplasmic, 13% mitochondrial, 13% e

51 The yeast proteins are defined in the Saccharomyces Genome D

52 Because few ubiquitylated yeast proteins are known to be degraded by autophagy und

53 he most abundant amino acid repeats found in yeast proteins are repeats of glutamine, asparagine, asp

54 lectrophoresis showed no evidence that other yeast proteins are substrates of this acetyltransferase.

55 Furthermore, we show that the yeast protein, ArgRIII, is an inositol-polyphosphate kin

56 The budding yeast protein Asr1 is the prototypical member of the RPC

57 68 Gal4 DNA binding domain fusions of yeast proteins associated with the actin cytoskeleton, s

58 king the localization and abundance of 5,330 yeast proteins at single-cell resolution under three dif

59 A number of yeast proteins bear putative cleavage sites for the ESP1

60 ein interaction network, we first classified yeast proteins by their evolutionary histories into isot

61 In this study, we examined yeast proteins by two-dimensional (2D) gel electrophores

62 ection of a pHis containing peptide from the yeast protein, Cdc10, suggests an unexpected role for hi

63 The essential yeast protein Cdc13 facilitates chromosome end replicati

64 RLI1 is an essential yeast protein closely related in sequence to two soluble

65 ARB1 is an essential yeast protein closely related to members of a subclass o

66 ur results suggest that, at least in budding yeast, protein-coding and noncoding Pol II-transcribed g

67 We classify the yeast protein complexes as either permanent or transient

68 We apply this scoring system to study yeast protein complexes by using the Saccharomyces cerev

69 s paper, we focus on a set of well-validated yeast protein complexes provided by Munich Information C

70 tic genomes and test data derived from known yeast protein complexes.

71 bears sequence homology to Cdc73p, a budding yeast protein component of the RNA polymerase II-associa

72 cture determination of Bud31p, a 157-residue yeast protein containing an unusual Zn3Cys9 cluster, dem

73 c interaction screens indicate that Bir1p, a yeast protein containing phylogenetically conserved anti

74 Analysis of gene ontology shows that yeast proteins containing predicted disordered segments,

75 ctions between Ure2p and naturally occurring yeast proteins could similarly affect [URE3] formation,

76 cular interactions that underlie the budding yeast protein-counting machinery.

77 hate group of the substrate, and the related yeast protein CPSF-100 (Ydh1) at 2.5 A resolution.

78 Prions formed by several other yeast proteins create their own phenotypes but share the

79 antibodies to approximately 5,000 different yeast proteins deposited on a glass slide and found that

80 employed for enriching phosphopeptides from yeast protein digests.

81 hobic core with the signal sequence from the yeast protein dipeptidyl aminopeptidase B, so that the r

82 iol oxidation status of almost 300 different yeast proteins distributed among various cellular compar

83 , a nuclear localization sequence, and small yeast protein domains that mediate either homodimerizati

84 Prompted by recent studies showing that the yeast protein Dot6 and its homolog Tod6 can bind to a PA

85 rt the identification of the remaining three yeast proteins (Dph1, -3, and -4) and show that all five

86 to the founding member of the subfamily, the yeast protein Drs2, which has been linked to ribosomal a

87 Based on homology to yeast proteins, DUE-B was previously classified as an am

88 ding protein-related proteins, including the yeast proteins encoded by the OSH gene family (OSH1-OSH7

89 study, we have characterized two homologous yeast proteins, Ent1p and Ent2p, which are similar to ma

90 We demonstrate that the fission yeast protein Epe1 stabilises silent chromatin, preventi

91 lomerase cofactor identified was the budding yeast protein Est1, which is conserved through humans.

92 the telomerase reverse transcriptase and the yeast proteins Est1p and Est3p as the only telomerase-sp

93 We show that the fission yeast protein Etd1 plays a central role in both of these

94 to screen nearly all of the 6,000 predicted yeast proteins, expressed as Gal4 DNA-binding domain fus

95 PhIAT labeling method was also applied to a yeast protein extract.

96 These are yeast protein extracts (YPE), cell walls and mannoprotei

97 munoprecipitates with Duo1p and Dam1p out of yeast protein extracts, and shows interdependent localiz

98 , and Duo1p/Dam1p coimmunoprecipitation from yeast protein extracts, these analyses indicated that Du

99 first purified 28 kinetochore proteins from yeast protein extracts.

100 be reclassified as mammalian isoforms of the yeast protein family Yip, Yip6b, and Yip6a, respectively

101 or the alkylation of peptide cosubstrates by yeast protein farnesyl transferase.

102 hat injection of a soluble copper-containing yeast protein Fet3p can restore iron homeostasis in phle

103 Here, we identify the budding-yeast protein Fin1 as a spindle-stabilizing protein whos

104 The yeast protein Fis1p has been shown to participate in mit

105 y of the N-domain, while both domains of the yeast protein fold in isolation into stable structures a

106 e pathways discovered by interrogating 4,733 yeast proteins for their ability to diminish toxicity in

107 Using a database of 200 yeast protein forms identified previously by top-down MS

108 A comparison of yeast proteins from wild type and a nat4 mutant by two-d

109 kov random field method to the prediction of yeast protein function based on multiple protein-protein

110 ould contribute to a global understanding of yeast protein function.

111 i mutant is WRB, a protein homologous to the yeast protein Get1, which is involved in the insertion o

112 form only a weak barrier for the majority of yeast proteins, given their monomeric size.

113 Many of these yeast proteins have orthologs in animal cells, suggestin

114 the catalytic role of this histidine in the yeast protein (His432) using a combination of X-ray crys

115 The fission yeast protein HMT2, a mitochondrial enzyme that can oxid

116 Eaf3p (Esa1p-associated factor-3 protein), a yeast protein homologous to the Drosophila dosage compen

117 es interaction approaches with mammalian and yeast protein homologs suggest that this mechanism is ev

118 executing sequence queries from a controlled yeast protein homology search benchmark.

119 l functionality is illustrated with a 36-kDa yeast protein identified from a processed cell extract a

120 The seven yeast proteins identified in our screen likely impact Ki

121 e ability of mouse Lon to substitute for the yeast protein in vivo.

122 s paper, we tested additional TPR-containing yeast proteins in a cell-free TBSV replication assay and

123 assay revealed similarity between human and yeast proteins in DNA binding.

124 DDP1/TIMM8a is similar to a family of yeast proteins in the mitochondrial intermembrane space

125 Here, we analyze levels of 4084 GFP-tagged yeast proteins in the progeny of a cross between a labor

126 t a two-proteome model (mixture of human and yeast proteins) in a sixplex isobaric labeling system to

127 family of proteins with homology to several yeast proteins, including Vps5p and Mvp1p, that are requ

128 e-stranded RNA virus, we overexpressed 5,500 yeast proteins individually in Saccharomyces cerevisiae,

129 Yeast protein insertion orientation (PIO) mutants were i

130 quately explains the genome-wide patterns of yeast protein interaction and human gene expression for

131 To study the evolution of the yeast protein interaction network, we first classified y

132 ccording to our measure in different baker's yeast protein interaction networks, outperforming existi

133 ating sets of proteins (MDSets) in human and yeast protein interaction networks.

134 that there is only a weak correlation in the yeast protein-interaction network.

135 core intermediary metabolism and that of the yeast protein-interaction network.

136 We used a set of benchmark yeast protein interactions to show that our approach out

137 Using databases of yeast protein interactions, we found that many nonessent

138 Portions of the yeast protein invertase (Suc2p) were inserted in-frame a

139 racted with LUC7L2, a mammalian homolog of a yeast protein involved in recognition of non-consensus s

140 its association with RAD51, a homolog of the yeast protein involved in the repair of DNA double-stran

141 ategy was used to (i) quantify low abundance yeast proteins involved in gene silencing, (ii) quantita

142 fied a strong signature of ERC between eight yeast proteins involved in meiotic crossing over, which

143 n containing proteins that are homologous to yeast proteins involved in protein trafficking.

144 We found that the yeast protein is rather stringent, only tolerating heter

145 Purified recombinant yeast protein is shown to be an Fe(II)-dependent sulfona

146 This protein is active and unlike the yeast protein, is a homodimer regardless of copper occup

147 with that of the human, bovine, and fission yeast proteins isolated from natural sources.

148 ngoid base production in cells inhibited for yeast protein kinase 1 (Ypk1) activity, that Ypk1 transm

149 Ypk2 (yeast protein kinase 2), a member of the cAMP-dependent,

150 ed ULK1 and ULK2, mammalian orthologs of the yeast protein kinase Atg1, which is required for autopha

151 n kinase N 1 (PKN1), which in part resembles yeast protein kinase C, has been shown to be under the c

152 Yeast protein kinase GCN2 stimulates the translation of

153 posed previously that the FHA2 domain of the yeast protein kinase Rad53 has dual specificity toward p

154 The yeast protein kinases Pkh1 and Pkh2, known sphingoid bas

155 -throughput method to identify substrates of yeast protein kinases that employs a collection of yeast

156 proteins that interact with the majority of yeast protein kinases using protein microarrays.

157 Of 122 known and predicted yeast protein kinases, 119 were overexpressed and analys

158 , the in vitro substrates recognized by most yeast protein kinases: we identified over 4,000 phosphor

159 The budding yeast protein Kip3p is a member of the conserved kinesin

160 Synbindin is structurally related to yeast proteins known to be involved in vesicle transport

161 These yeast proteins, like HIV-1 gp120, contain a large number

162 The first domain of the yeast protein, located between residues 50 and 84, was n

163 The paralogous yeast proteins Lsb1 and Lsb2 bind the actin assembly pro

164 tor, Skb15, as well as the essential budding yeast protein, MAK11.

165 ArnT displays distant similarity to yeast protein mannosyltransferases.

166 e (SAH) analogues that are targeted toward a yeast protein methyltransferase RMT1.

167 TAP, the human homologue of the yeast protein Mex67p, has been proposed to serve a role

168 The two yeast proteins Mlp1p and Mlp2p (homologues of the verteb

169 We show that the yeast proteins Mlp1p and Mlp2p are necessary components

170 s class II mMOB1, a mammalian homolog of the yeast protein MOB1, and show that its phosphorylation ap

171 The budding yeast proteins Mrc1 and Tof1 associate with the putative

172 A recognition motifs, that is related to the yeast protein Mrd1p.

173 Yeast protein Mss116 greatly accelerates intron folding

174 A computational analysis revealed two yeast proteins, Mtq1p and Mtq2p, that have strong sequen

175 bed the nucleic acid binding properties of a yeast protein, Nab2, that contains this zinc finger moti

176 Here, we show that the budding yeast proteins Ndc80p, Nuf2p, Spc24p and Spc25p interact

177 n, we demonstrate that human Dullard and the yeast protein Nem1p perform similar functions in mammali

178 The CAI value distribution for identified yeast proteins now more closely approximates that predic

179 We find that the yeast protein Nvj2p promotes the nonvesicular transfer o

180 adapt recent results on the localization of yeast proteins obtained by Snyder and colleagues using a

181 This work also revealed that additional yeast proteins participate in reducing beta-keto esters,

182 Previously, we demonstrated that the yeast protein Pbp1p associates with poly(A)-binding prot

183 how that an isolated peptide ligand from the yeast protein Pbs2 recognizes its biological partner, th

184 Bni4 also associates with the yeast protein phosphatase (PP1) catalytic subunit, Glc7.

185 in with similarity to Sds22p, a regulator of yeast protein phosphatase 1 (PP1) activity in the nucleu

186 ow that the catalytic subunit of the budding yeast protein phosphatase 1 (PP1) homolog, Glc7, regulat

187 d upon deletion of the catalytic subunits of yeast protein phosphatase 2A, suggesting that lower PKA

188 Budding yeast protein phosphatase Cdc14 is sequestered in the nu

189 phosphatase drives this reversal in budding yeast, protein phosphatase 1 (PP1) and protein phosphata

190 gical networks of moderate size, such as the yeast protein physical interaction network, they either

191 ing homology to annotated yeast ORFs and non-yeast proteins plus a simple region extension procedure,

192 ates, were evaluated by considering over 450 yeast proteins previously examined in numerous studies,

193 A comprehensive analysis uncovered a set of yeast proteins promoting protein-based inheritance that

194 tioning algorithm we identify subnetworks in yeast protein-protein interaction (PPI), genetic interac

195 When averaged over the full yeast protein-protein interaction and transcriptional re

196 cs and microarray datasets and represent the yeast protein-protein interaction network as a weighted

197 The integrity of the yeast protein-protein interaction network is maintained

198 h have an average discard rate of 45% on the yeast protein-protein interaction network.

199 singly, by integrating topologies of bakers' yeasts protein-protein interaction, genetic interaction

200 nd MOG-5 proteins are closely related to the yeast proteins PRP16, PRP2, and PRP22, respectively.

201 y, symplekin has significant similarity to a yeast protein, PTA1, that is a component of the yeast po

202 st structure of an FHA domain, FHA2 from the yeast protein Rad53, and demonstrated that FHA2 binds to

203 Recently, we reported that two homologous yeast proteins, Rai1 and Dxo1, function in a quality con

204 Overexpression of the yeast protein Rcn1p or the human homologs DSCR1 or ZAKI-

205 to the disaggregation process, providing the yeast protein-recovery system with substrate specificity

206 icient BMV RNA replication requires Lsm1p, a yeast protein related to core RNA splicing factors but s

207 Mus81, a fission yeast protein related to the XPF subunit of ERCC1-XPF nu

208 Hsp104, a yeast protein-remodeling factor of the AAA+ (ATPases ass

209 re, we characterize mto2p as a novel fission yeast protein required for MT nucleation from noncentros

210 ly endosomal protein homologous to Vps27p, a yeast protein required for vesicular trafficking.

211 Sla1 and Rvs167 are yeast proteins required for receptor internalization and

212 This study identified some of the yeast proteins responsible for DNA repair synthesis duri

213 Kinetic analysis of the budding yeast proteins revealed that the catalytic efficiency of

214 ybrid analysis of the 17 soluble class E Vps yeast proteins revealed that Vps46p/Did2p interacts with

215 Kinetic analysis of the wild-type yeast protein reveals a predominant fast-folding phase w

216 Furthermore, the prion conformation of the yeast protein Rnq1 and the level of expression of a suit

217 d polyQ aggregation and was dependent on the yeast protein Rnq1 in its prion form.

218 The yeast protein Rrf1p encoded by the FIL1 nuclear gene bea

219 malian proteins amphiphysin and Bin1 and the yeast proteins Rvs167p and Rvs161p, has been implicated

220 identified and characterized two homologous yeast proteins, Sbe2p and Sbe22p, through their suppress

221 oteins pass the NPC by simple diffusion, two yeast proteins, ScSrc1/ScHeh1 and ScHeh2, are actively i

222 Here, we identify the fission yeast protein Sdj1 as the orthologue of DJ-1 and calcula

223 al polymerase, Mip1p, as bait identified the yeast protein Sed1p.

224 The intrinsically disordered yeast protein Sem1 (DSS1 in mammals) participates in mul

225 red some unexpected variances within several yeast protein sequences due to amino acid mutations and/

226 Simulations generating yeast protein sets enriched for identification propensit

227 A demo of PPFBM that annotates each input Yeast protein (SGD (Saccharomyces Genome Database).

228 t RAR1 interacts with plant orthologs of the yeast protein SGT1, an essential regulator in the cell c

229 on of the Src homology 3 (SH3) domain of the yeast protein Sho1 with its cognate proline-rich (PR) se

230 Yeast proteins show very little overdispersion, while ma

231 cal to ubiquitin but is 48% identical to the yeast protein Smt3.

232 served coiled-coil protein homologous to the yeast protein Snf7, a key component in the ESCRT-III (en

233 The budding yeast protein Spo13 plays a key role in preventing centr

234 We have identified a pair of related yeast proteins, Sro7p and Sro77p, based on their ability

235 By analyzing a range of yeast protein standards, we found that the high mass acc

236 The yeast protein Stu2 belongs to the XMAP215 family of cons

237 The yeast protein Sua5 has been reported previously to be re

238 The structural similarity of the E. coli and yeast proteins suggests that most fRMsrs use three cyste

239 For the yeast protein Sup35, conversion to amyloid-like fibrils

240 e N-terminal prion-determining domain of the yeast protein Sup35.

241 a GPI-anchored version of the amyloidogenic yeast protein Sup35NM (Sup35GPI) was expressed in neuron

242 d by NM, the prion-determining region of the yeast protein Sup35p.

243 on domain-containing fragment (Sup35NM) of a yeast protein Sup35p.

244 ctional homologue of the recently identified yeast protein Tad1p.

245 is demonstrated in an experiment to identify yeast protein targets of the immunosuppressive drug, cyc

246 Here we identify a yeast protein, termed Def1, which forms a complex with R

247 NAs encoding human and mouse homologues of a yeast protein, termed peroxisomal membrane protein 20 (P

248 pICln interacts directly with a homolog of a yeast protein that binds a PAK-like kinase and participa

249 tin regulating kinase 1) was identified as a yeast protein that binds to Sla2p, an evolutionarily con

250 Excess Sup35p, an essential yeast protein that can exist as the [PSI(+)] prion, inhi

251 Among these proteins is ecm29p, a 200-kDa yeast protein that contains numerous HEAT repeats as wel

252 and SNX2 are mammalian orthologs of Vps5p, a yeast protein that is a subunit of a large multimeric co

253 is an Src homology 3 (SH3) domain-containing yeast protein that is involved in a variety of cellular

254 Fin1 is a budding yeast protein that localizes to the poles and microtubul

255 Moe1 is a conserved fission yeast protein that negatively affects microtubule stabil

256 are the first demonstration of an endogenous yeast protein that requires the exposure of the alpha-am

257 y with Nud1p and Cdc11p, budding and fission yeast proteins that anchor regulatory pathways involved

258 ffecting growth and viability, implying that yeast proteins that are essential under laboratory condi

259 of a strategy to identify human homologs of yeast proteins that are known to be involved in Golgi ho

260 -like antibodies, we searched for endogenous yeast proteins that could bind to 2G12 in a panel of Sac

261 revealed that it has homology to a group of yeast proteins that function in the biosynthesis of very

262 PIN(+)] or [URE3] or overexpression of other yeast proteins that have stretches of polar residues sim

263 his approach led to the identification of 58 yeast proteins that interacted with p33 replication prot

264 Based on their homology to the yeast proteins that regulate the Ypt7 GTP binding state,

265 d silencing screen was performed to identify yeast proteins that, when tethered to a telomere, suppre

266 With human proteins, unlike yeast proteins, the acetylation of free core histones by

267 In the yeast protein, three membrane-spanning domains were iden

268 gh localizations have been measured for many yeast proteins through systematic GFP fusions, similar s

269 The homologous yeast protein Tif6p was also phosphorylated in vivo in y

270 A report that a switch of a yeast protein to a 'prion' state triggers diverse phenot

271 k established that mutational switching of a yeast protein to a mammalian-like cytokine was specific

272 ly, we used live-cell imaging of six budding-yeast proteins to define a pathway for association of re

273 d revealed approximately 16% of the detected yeast proteins to have multiple phosphorylation isoforms

274 ins, the antibodies cross-reacted with other yeast proteins to varying degrees.

275 The poly(ADP-ribosyl)ation of three of these yeast proteins, together with two human homologues, was

276 In budding yeast, protein transport between the trans-Golgi network

277 equires in addition one of a pair of related yeast proteins, Tre1 and Tre2, that also contain PPxY mo

278 Currently, the DB hosts information on 5330 yeast proteins under three external perturbations (DTT,

279 er the inducible expression of an endogenous yeast protein was also less efficient in the ydj1-151 st

280 5.7) 2D gel in which 0.5 mg of total soluble yeast protein was separated.

281 rog (approximately 600 pmol) sample of total yeast protein, we identify 1,252 phosphorylation sites o

282 Interestingly, 36 yeast proteins were identified previously by various scr

283 tifs (CX(2)CXC and twin CX(2)C) in human and yeast proteins were perfectly aligned.

284 This is apparently the first example of a yeast protein where mutagenesis of AUG1 does not lead to

285 script 4)-associated protein (SAP) family of yeast proteins, which are involved in regulation of the

286 complex, Derlin-1, is a homologue of Der1, a yeast protein whose inactivation prevents the eliminatio

287 aining and testing set of approximately 1300 yeast proteins with an experimentally known localization

288 veloping our system, we apply it to the 4700 yeast proteins with currently unknown localization and e

289 larly affect [URE3] formation, we identified yeast proteins with domains that are compositionally sim

290 predictions for individual proteins (on the yeast proteins with known localization, 92% versus 74%).

291 ometry (LC-MS/MS) run, we have identified 22 yeast proteins with molecular weights from 14 to 35 kDa.

292 Furthermore, yeast proteins with NORS regions had more protein-protei

293 covered an association of 77 uncharacterized yeast proteins with ribosomes.

294 osphorylates two recently identified fission yeast proteins with RS repeats, Srp1 and Srp2, in vitro.

295 CAF130 and CAF40 are two unique yeast proteins, with CAF40 displaying extensive homology

296 by a simple and automated procedure for 192 yeast proteins, with positive responses identified by th

297 We found that yeast protein YLR143W is the diphthamide synthetase cata

298 The yeast protein Yor1p is a useful model to study the bioge

299 The yeast protein Yrb2p participates in this pathway and bin

300 The yeast protein Zim17 belongs to a unique class of co-chap