Polyphosphate Deficiency Affects the Sliding Motility and Biofilm Formation of Mycobacterium smegmatis
Inorganic polyphosphate (polyP) is a ubiquitous linear polymer of hundreds of orthophosphate (Pi) residues linked by ATP-like, high-energy, phosphoanhydride bonds. The gene Rv1026 in Mycobacterium tuberculosis encodes a putative exopolyphosphatase which progressively hydrolyzes the terminal residues of polyP to liberate Pi. Rv1026 was cloned into the expressive plasmid pMV261. The resulting plasmid pRv1026 and the plasmid pMV261 were transformed into M. smegmatis strain mc2155 by electroporation. The recombinant M. smegmatis (pRv1026) showed relatively decreased polyP concentration and a phenotype different from the M. smegmatis (pMV261) in sliding motility and biofilm formation. The surfactant Tween 80 can enhance this effect on the sliding motility and biofilm formation of M. smegmatis. There are four different peaks between the gas chromatography of cellular wall fatty acid of the M. smegmatis (pRv1026) and the M. smegmatis (pMV261). These results indicate that polyP deficiency can affect the fatty acid composition of cellular wall and these alteration of cell wall might elucidate the reductive ability of strains to slide and form biofilm. This investigation provides novel recognition about the role of Rv1026, which provides novel clues for further study on the physiological role of Rv1026 in M. tuberculosis.
KeywordsMycobacterium Malachite Green Mycobacterium Smegmatis Strain Mc2155 Cell Surface Property
The study is Supported by the National key infectious disease project (No. 2008ZX10003-006, No. 2008ZX10003-001), national natural science foundation (No. 81071316,90813019), Excellent PhD thesis fellowship of southwest university (No. kb2009010, No. ky2009009), The Fundamental Research Funds for the Central Universities (XDJK2009A003) and Natural Science Foundation Project of CQ CSTC (CSTC, 2010BB5002).
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