Title

Authors

Affiliation

¹Centre for Agricultural Bioinformatics, Indian Agricultural Statistics Research Institute, Pusa, New Delhi – 110 012; ²National Bureau of Agriculturally Important Microorganisms, Mau Nath Bhanjan, UP – 275 101

Email

samir@iasri.res.in; sanjuktark@iasri.res.in; *Corresponding authors

Article Type

Hypothesis

Date

Received September 22, 2012; Accepted October 06, 2012; Published November 13, 2012

Chromohalobacter salexigens, a Gammaproteobacterium belonging to the family Halomonadaceae, shows a broad salinity range for growth. In order to reveal the factors influencing architecture of protein coding genes in C. salexigens, pattern of synonymous codon usage bias has been investigated. Overall codon usage analysis of the microorganism revealed that C and G ending codons are predominantly used in all the genes which are indicative of mutational bias. Multivariate statistical analysis showed that the genes are separated along the first major explanatory axis according to their expression levels and their genomic GC content at the synonymous third positions of the codons. Both N_C plot and correspondence analysis on Relative Synonymous Codon Usage (RSCU) indicates that the variation in codon usage among the genes may be due to mutational bias at the DNA level and natural selection acting at the level of mRNA translation. Gene length and the hydrophobicity of the encoded protein also influence the codon usage variation of genes to some extent. A comparison of the relative synonymous codon usage between 10% each of highly and lowly expressed genes determines 23 optimal codons, which are statistically over represented in the former group of genes and may provide useful information for salt-stressed gene prediction and gene-transformation. Furthermore, genes for regulatory functions; mobile and extrachromosomal element functions; and cell envelope are observed to be highly expressed. The study could provide insight into the gene expression response of halophilic bacteria and facilitate establishment of effective strategies to develop salt-tolerant crops of agronomic value.

Keywords

Codon usage pattern, Correspondence analysis, Relative synonymous codon usage, Mutational bias, Halophilic bacteria.

Citation

Sanjukta et al. Bioinformation 8(22): 1087-1095 (2012)
 

Edited by

P Kangueane

ISSN

0973-2063

Publisher

Biomedical Informatics

License

This is an Open Access article which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. This is distributed under the terms of the Creative Commons Attribution License.