Chlamydophila pneumoniae HflX belongs to an uncharacterized family of conserved GTPases and associates with the Escherichia coli 50S large ribosomal subunit

Polkinghorne, Adam, Ziegler, Urs, Pospischil, Andreas, Timms, Peter, & Vaughan, Lloyd (2008) Chlamydophila pneumoniae HflX belongs to an uncharacterized family of conserved GTPases and associates with the Escherichia coli 50S large ribosomal subunit. Microbiology, 154(11), pp. 3537-3546.

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Predicted members of the HflX subfamily of phosphate-binding-loop guanosine triphosphatases (GTPases) are widely distributed in the bacterial kingdom but remain virtually uncharacterized. In an attempt to understand mechanisms used for regulation of growth and development in the chlamydiae, obligate intracellular and developmentally complex bacteria, we have begun investigations into chlamydial GTPases; we report here what appears to be the first analysis of a HflX family GTPase using a predicted homologue from Chlamydophila pneumoniae. In agreement with phylogenetic predictions for members of this GTPase family, purified recombinant Cp. pneumoniae HflX was specific for guanine nucleotides and exhibited a slow intrinsic GTPase activity when incubated with [gamma-(32)P]GTP. Using HflX-specific monoclonal antibodies, HflX could be detected by Western blotting and high-resolution confocal microscopy throughout the vegetative growth cycle of Cp. pneumoniae and, at early time points, appeared to partly localize to the membrane. Ectopic expression of Cp. pneumoniae HflX in Escherichia coli revealed co-sedimentation of HflX with the E. coli 50S large ribosomal subunit. The results of this work open up some intriguing possibilities for the role of GTPases belonging to this previously uncharacterized family of bacterial GTPases. Ribosome association is a feature shared by other important conserved GTPase families and more detailed investigations will be required to delineate the role of HflX in bacterial ribosome function.

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ID Code: 17094
Item Type: Journal Article
Refereed: Yes
Additional Information: Articles free to read on journal website after 12 months
Keywords: GTP Phosphohydrolases, Amino Acid Sequence, Bacterial Proteins, Chlamydophila pneumoniae, Evolution, Molecular
DOI: 10.1099/mic.0.2008/022137-0
ISSN: ISSN: 1350-0872
Subjects: Australian and New Zealand Standard Research Classification > BIOLOGICAL SCIENCES (060000) > BIOCHEMISTRY AND CELL BIOLOGY (060100) > Biochemistry and Cell Biology not elsewhere classified (060199)
Divisions: Past > QUT Faculties & Divisions > Faculty of Science and Technology
Current > Institutes > Institute of Health and Biomedical Innovation
Past > Schools > School of Life Sciences
Copyright Owner: Copyright 2008 Society for General Microbiology
Deposited On: 05 Jan 2009 04:38
Last Modified: 05 Feb 2015 06:05

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