[Influence of amino acid and dipeptide composition on protein stability of piezophilic microbes].
OBJECTIVE
To compare the amino acid and dipeptide composition of proteins from piezophilic and non-piezophilic microbes is of great significance for understanding the stability of piezophilic protein and directed mutation of them.


METHODS
The amino acids of different secondary structure and the dipeptides of 639 orthologs proteins were counted and the deviation of them were calculated.


RESULTS
The amino acid composition based on secondary structure and the dipeptide composition reveals some common trends. The amino acids vary widely in beta sheet and coil. In beta sheet, piezophilic proteins contain more amino acids such as Val, Ile and Leu, whereas less Arg, Lys and Asp; in coil, piezophilic proteins contained more amino acids such as Val and Ile, whereas less Gly and Pro. On the other hand, piezophilic proteins contain more dipeptides such as YM, MN, KD, QC, CI, MW, MM, CY, WQ, HC, RC and QH, whereas less dipeptides such as TW, MS, VD, DH, YE, CT, MW, CF, CK, CM, MY, QI, TH, MQ, QQ and MC.


CONCLUSIONS
Dipeptide contains more structure and sequence information than amino acid, and it will be more helpful for understanding the mechanism of piezophilic adaptation and guiding the engineering of proteins.
Zhang
Guangya
G
Department of Bioengineering and Biotechnology, Huaqiao University, Xiamen 361021, China. zhgyghh@hqu.edu.cn
Li
Hongchun
H
Gao
Jiaqiang
J
Fang
Baishan
B
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry*; D019843:Archaeal Proteins / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry*; D004151:Dipeptides / Q000737:chemistry*; D008969:Molecular Sequence Data; D011487:Protein Conformation; D055550:Protein Stability; D019711:Pyrococcus / Q000737:chemistry*; D020592:Shewanella / Q000737:chemistry*
D000596:Amino Acids; D019843:Archaeal Proteins; D001426:Bacterial Proteins; D004151:Dipeptides