Functional characterization of two members of histidine phosphatase superfamily in Mycobacterium tuberculosis

BMC Microbiology

Research Article

Olabisi Oluwabukola Coker¹  Prasit Palittapongarnpim²  Pijug Summpunn³  Saradee Warit⁴  Therdsak Prammananan⁴  Kamolchanok Rukseree⁵ 

[1] Department of Microbiology, Faculty of Science, Mahidol University, Rama 6 Road, 10400, Bangkok, Thailand;Department of Microbiology, Faculty of Science, Mahidol University, Rama 6 Road, 10400, Bangkok, Thailand;National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 12120, PathumThani, Thailand;Department of Microbiology, Faculty of Science, Mahidol University, Rama 6 Road, 10400, Bangkok, Thailand;School of Agricultural Technology, Walailak University, 80161, Nakhon Si, Thammarat, Thailand;National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 12120, PathumThani, Thailand;National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 12120, PathumThani, Thailand;Mahidol University, Amnatcharoen Campus, 37000, Muang, Amnatcharoen, Thailand;

关键词: Rv2135c;    Rv0489;    Acid phosphatase;    Hypothetical protein;    Histidine phosphatase superfamily;    Phosphoglycerate mutase;    Mycobacterium tuberculosis;   

DOI  :  10.1186/1471-2180-13-292

 received in 2013-07-05, accepted in 2013-12-07,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundFunctional characterization of genes in important pathogenic bacteria such as Mycobacterium tuberculosis is imperative. Rv2135c, which was originally annotated as conserved hypothetical, has been found to be associated with membrane protein fractions of H37Rv strain. The gene appears to contain histidine phosphatase motif common to both cofactor-dependent phosphoglycerate mutases and acid phosphatases in the histidine phosphatase superfamily. The functions of many of the members of this superfamily are annotated based only on similarity to known proteins using automatic annotation systems, which can be erroneous. In addition, the motif at the N-terminal of Rv2135c is ‘RHA’ unlike ‘RHG’ found in most members of histidine phosphatase superfamily. These necessitate the need for its experimental characterization. The crystal structure of Rv0489, another member of the histidine phosphatase superfamily in M. tuberculosis, has been previously reported. However, its biochemical characteristics remain unknown. In this study, Rv2135c and Rv0489 from M. tuberculosis were cloned and expressed in Escherichia coli with 6 histidine residues tagged at the C terminal.ResultsCharacterization of the purified recombinant proteins revealed that Rv0489 possesses phosphoglycerate mutase activity while Rv2135c does not. However Rv2135c has an acid phosphatase activity with optimal pH of 5.8. Kinetic parameters of Rv2135c and Rv0489 are studied, confirming that Rv0489 is a cofactor dependent phosphoglycerate mutase of M. tuberculosis. Additional characterization showed that Rv2135c exists as a tetramer while Rv0489 as a dimer in solution.ConclusionMost of the proteins orthologous to Rv2135c in other bacteria are annotated as phosphoglycerate mutases or hypothetical proteins. It is possible that they are actually phosphatases. Experimental characterization of a sufficiently large number of bacterial histidine phosphatases will increase the accuracy of the automatic annotation systems towards a better understanding of this important group of enzymes.

【 授权许可】

Unknown   
© Coker et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.