Deletion of the rpoZ gene, encoding the ${\omega}$ subunit of RNA polymerase,results in pleiotropic surface related phenotypes in Mycobacterium smegmatis

Mathew, Renjith and Mukherjee, Raju and Radhakrishnan, Balachandar and Chatterji, Dipankar (2006) Deletion of the rpoZ gene, encoding the ${\omega}$ subunit of RNA polymerase,results in pleiotropic surface related phenotypes in Mycobacterium smegmatis. In: Microbiology, 152 (6). pp. 1741-1750.

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Abstract

The omega subunit, the smallest subunit of bacterial RNA polymerase, is known to be involved in maintaining the conformation of the beta' subunit and aiding its recruitment to the rest of the core enzyme assembly in Escherichia coli. It has recently been shown in Mycobacterium smegmatis, by creating a deletion mutation of the rpoZ gene encoding omega that the physiological role of the m subunit also includes providing physical protection to beta. Interestingly, the mutant had altered colony morphology. This paper demonstrates that the mutant mycobacterium has pleiotropic phenotypes including reduced sliding motility and defective biofilm formation.Analysis of the spatial arrangement of biofilms by electron microscopy suggests that the altered phenotype of the mutant arises from a deficiency in generation of extracellular matrix. Complementation of the mutant strain with a copy of the wild-type rpoZ gene integrated in the bacterial chromosome restored both sliding motility and biofilm formation to the wild-type state, unequivocally proving the role of omega in the characteristics observed for the mutant bacterium. Analysis of the cell wall composition demonstrated that the mutant bacterium had an identical glycopeptidolipid profile to the wild-type, but failed to synthesize the short-chain mycolic acids characteristic of biofilm growth in M. smegmatis

Item Type:	Journal Article
Publication:	Microbiology
Publisher:	Society for General Microbiology
Additional Information:	Copyright of this article belongs to Society for General Microbiology.
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit
Date Deposited:	19 Mar 2009 11:16
Last Modified:	19 Sep 2010 04:55
URI:	http://eprints.iisc.ac.in/id/eprint/17058

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