| dc.description.abstract | Various strains of the genus Bifidobacterium
are crucial members of the human, animal and insect gut,
associated with beneficial probiotic activities. An extensive
analysis on codon and amino acid usage of the GC rich
genus Bifidobacterium has been executed in the present
study. Multivariate statistical analysis revealed a coupled
effect of GC compositional constraint and natural selection
for translational efficiency to be operative in producing the
observed codon usage variations. Gene expression level
was inferred to be the most crucial factor governing the
codon usage patterns. Amino acid usage was found to be
influenced significantly by hydrophobic and aromatic
character of the encoded proteins. Gene expressivity and
protein energetic cost also had considerable impact on the
differential mode of amino acid usage. The genus was
found to strictly obey the cost-minimization hypothesis as
was reflected from the amino acid usage patterns of the
potential highly expressed gene products. Evolutionary
analysis revealed that the highly expressed genes were
candidates to extreme evolutionary selection pressure and
indicated a high degree of conservation at the proteomic
level. Interestingly, the complimentary strands of replica-
tion appeared to evolve under similar evolutionary constraints which might be addressed as a consequence of
absence of replicational selection and lack of strand-
specific asymmetry among the members of the genus.
Thus, the present endeavor confers considerable know-how
pertaining to the codon and amino acid usage intricacies in
Bifidobacterium and might prove handy for further scien-
tific investigations associated with the concerned domain. | en_US |
