dc.contributor.author	Gey van Pittius, Nicolaas C.
dc.contributor.author	Sampson, Samantha L.
dc.contributor.author	Lee, Hyeyoung
dc.contributor.author	Kim, Yeun
dc.contributor.author	Van Helden, Paul D.
dc.contributor.author	Warren, Robin M.
dc.date.accessioned	2010-12-14T13:53:33Z
dc.date.available	2010-12-14T13:53:33Z
dc.date.issued	2006-11
dc.date.updated	2010-11-09T12:59:25Z
dc.description	Includes bibliography
dc.description.abstract	Background: The PE and PPE multigene families of Mycobacterium tuberculosis comprise about 10% of the coding potential of the genome. The function of the proteins encoded by these large gene families remains unknown, although they have been proposed to be involved in antigenic variation and disease pathogenesis. Interestingly, some members of the PE and PPE families are associated with the ESAT-6 (esx) gene cluster regions, which are regions of immunopathogenic importance, and encode a system dedicated to the secretion of members of the potent T-cell antigen ESAT-6 family. This study investigates the duplication characteristics of the PE and PPE gene families and their association with the ESAT-6 gene clusters, using a combination of phylogenetic analyses, DNA hybridization, and comparative genomics, in order to gain insight into their evolutionary history and distribution in the genus Mycobacterium. Results: The results showed that the expansion of the PE and PPE gene families is linked to the duplications of the ESAT-6 gene clusters, and that members situated in and associated with the clusters represent the most ancestral copies of the two gene families. Furthermore, the emergence of the repeat protein PGRS and MPTR subfamilies is a recent evolutionary event, occurring at defined branching points in the evolution of the genus Mycobacterium. These gene subfamilies are thus present in multiple copies only in the members of the M. tuberculosis complex and close relatives. The study provides a complete analysis of all the PE and PPE genes found in the sequenced genomes of members of the genus Mycobacterium such as M. smegmatis, M. avium paratuberculosis, M. leprae, M. ulcerans, and M. tuberculosis. Conclusion: This work provides insight into the evolutionary history for the PE and PPE gene families of the mycobacteria, linking the expansion of these families to the duplications of the ESAT-6 (esx) gene cluster regions, and showing that they are composed of subgroups with distinct evolutionary (and possibly functional) differences.	en_ZA
dc.description.version	Peer Reviewed
dc.format.extent	31 p. : co. ill.
dc.identifier.citation	Gey van Pittius, NC, Sampson, SL, Lee, H, Kim, Y, Van Helden, PD & Warren, RM 2006, 'Evolution and expansion of the Mycobacterium tuberculosis PE and PPE multigene families and their association with the duplication of the ESAT-6 (esx) gene cluster regions', BMC Evolutionary Biology, 6(1):95.	en_ZA
dc.identifier.issn	1471-2148
dc.identifier.other	http://dx.doi.org/10.1186/1471-2148-6-95
dc.identifier.uri	http://hdl.handle.net/10019.1/5120
dc.language.iso	en_ZA	en_ZA
dc.language.rfc3066	en
dc.publisher	BioMed Central	en_ZA
dc.rights.holder	Gey van Pittius et al.; licensee BioMed Central Ltd.	en_ZA
dc.subject	Mycobacterium tuberculosis	en_ZA
dc.subject	ESAT-6 (esx) gene cluster regions	en_ZA
dc.title	Evolution and expansion of the Mycobacterium tuberculosis PE and PPE multigene families and their association with the duplication of the ESAT-6 (esx) gene cluster regions	en_ZA
dc.type	Article	en_ZA

Evolution and expansion of the Mycobacterium tuberculosis PE and PPE multigene families and their association with the duplication of the ESAT-6 (esx) gene cluster regions

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