Title

Comparative sequence analysis of acid sensitive/resistance proteins in Escherichia coli and Shigella flexneri

Authors

Selvaraj Manikandan^{1, $}, Seetharaaman Balaji ^{2, $}, Anil Kumar¹ and Rita kumar^{1, *}

^$Both the authors contributed equally. ¹ Institute of Genomics and Integrative Biology, Mall Road, Delhi - 110007, India; ² Lecturer, Department of Biotechnology, Manipal Institute of Technology, Manipal University, Manipal - 576104, India

Phone

91 11 27662133

91 11 27667471

Email

rita@igib.res.in; * Corresponding author

Article Type

Hypothesis

Date

received September 17, 2007; revised October 25, 2007; accepted November 22, 2007; published online December 07, 2007

The molecular basis for the survival of bacteria under extreme conditions in which growth is inhibited is a question of great current interest. A preliminary study was carried out to determine residue pattern conservation among the antiporters of enteric bacteria, responsible for extreme acid sensitivity especially in Escherichia coli and Shigella flexneri. Here we found the molecular evidence that proved the relationship between E.coli and S.flexneri. Multiple sequence alignment of the gadC coded acid sensitive antiporter showed many conserved residue patterns at regular intervals at the N-terminal region. It was observed that as the alignment approaches towards the C-terminal, the number of conserved residues decreases, indicating that the N-terminal region of this protein has much active role when compared to the carboxyl terminal. The motif, FHLVFFLLLGG, is well conserved within the entire gadC coded protein at the amino terminal. The motif is also partially conserved among other antiporters (which are not coded by gadC) but involved in acid sensitive/resistance mechanism. Phylogenetic cluster analysis proves the relationship of Escherichia coli and Shigella flexneri. The gadC coded proteins are converged as a clade and diverged from other antiporters belongs to the amino acid-polyamine-organocation (APC) superfamily.

amino acid -polyamine-organocation (APC); Glutamate decarboxylase (GadC); bacteria; sequence; proteins

Citation

Manikandan, et al., Bioinformation 2(4): 145-152 (2007)

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.