Abstract: To see the effect of temperature on the codon and amino acid usage
in phages, codon and amino acid usage of 13 phages of extremely thermophilic
prokaryotes were compared with that of 14 phages of mesophilic prokaryotes.
Correspondence analysis on RSCU values of two groups of phage genomes clearly
shows that phages are separated along the second major axis according to their
growth temperature, whereas, they are separated along the first major axis
according to their GC content. Correspondence analysis on RAAU values of two
groups of phages clearly shows that protein encoding genes of the phages along
the second major axis are highly correlated with the GRAVY, aromaticity and
cysteine content. Moreover, correspondence analysis on the regular and
irregular structures of proteins of phages infecting extremely thermophilic
prokaryotes reveals that temperature is one of the factors responsible for most
significant differentiation of codon and amino acid usages variation in these
phages.
Keywords: Relative synonymous codon usage (RSCU), relative amino acid usage (RAAU), correspondence analysis (CA), frequency of G+C at the synonymous third codon
positions (GC3s), covalently closed circular (ccc) DNA, GRAVY, aromaticity, cysteine content, thermophilic prokaryotes, mesophilic prokaryotes