Author(s)

Zhiping Zhao, Xin Nie, Zaixin Li, Zhi Zhang, Jie Ding, Wanru Xie

School of Chemistry and Pharmaceutical Engineering, Sichuan University of Science & Engineering, Zigong, China.

Antibiotic resistant Escherichia coli strains are becoming more common recently. OmpA is a very important antigen protein of E. coli, which consists of two separate domains, N-terminal and C-terminal domain. The N-terminal domain contains eight β- barrel regions that plays important roles in the multifaceted functions of OmpA. In the present study, we cloned a mutant OmpA gene from a multi-antibiotic resistant E. coli strain. Sequence analysis indicated that the N-terminal DNA sequence of the mutant OmpA shared 81.05% homology with the modeled OmpA from E. coli K12 and the N-terminal amino acid sequence of the mutant OmpA was 81.22% identical to that of the E. coli K12 OmpA. Moreover, several amino acids located in the β-barrel region were mutated. The mutant OmpA was expressed in BL21 suggested by SDS-PAGE. Resistance to environmental stress assay indicated that the N-terminus mutant OmpA still possessed excellent activities in pH, temperature and osmotic pressure resistance. Our pre- sent study may supply insights into better and deeper understand the relationships between OmpA N-terminal regions and its functions in environmental stress conditions and the mechanisms on antibiotic resistance of E. coli.

Antibiotic Resistance; OmpA; Environmental Stress; E. coli

Zhao, Z. , Nie, X. , Li, Z. , Zhang, Z. , Ding, J. and Xie, W. (2013) Amino terminus mutant OmpA from an isolated antibiotic resistant Escherichia coli still possess resistance to environmental stresses. Advances in Biological Chemistry, 3, 108-113. doi: 10.4236/abc.2013.31014.