Computer based software such as the SignalP v3.0, TargetP v1.01, big-PI predictor and TMHMM v2.0 were combined topredict the signal peptides, and the signal peptide-dependent secreted proteins among the 6 700 ORFs in genome ofSaccharomyces cerevisiae. The results showed that 163 proteins were the secreted ones containing signal peptides, andthey were secreted via Sec pathway. Among the 163 predicted secreted proteins, the signal peptides of 47 secretedproteins included only the H-domain and C-domain, without N-domain, but the signal peptides of other 116 secretedproteins included all the three domains. There were differences in the constitution of signal peptides between the secretedproteins of S. cerevisiae and of Candida albicans, but the length and amino acids types of their signal peptides weresimilar in general. Few of the same signal peptides occurred in the secreted proteins of S. cerevisiae genome, and thehomology could be compared among the secreted proteins with the same signal peptides. The BLAST 2 SEQUENECESand CLUSTAL W were used to align the two protein sequences and multi-protein sequences, respectively. The alignmentresult indicated that homology of these sequences with the same signal peptide was very highly conservative in aminoacid of complete gene. The effect of the signal peptides in S. cerevisia on expression of foreign eukaryotic secretedproteins is discussed in this paper.
YANG JingLI Cheng-yunWANG Yun-yueZHU You-yongLI Jin-binHE Xia-hongZHOU Xiao-gangLIU LinYE Yan-fen
