Serine threonine protein kinases of mycobacterial genus: phylogeny to function

Azeet Narayan, Preeti Sachdeva, Kirti Sharma, Adesh K. Saini, Anil K. Tyagi, Yogendra Singh
2007 Physiological Genomics  
Serine/threonine protein kinases (STPKs) are known to act as sensors of environmental signals that thereby regulate developmental changes and host pathogen interactions. In this study, we carried out comparative genome analysis of six completely sequenced pathogenic and nonpathogenic mycobacterial species to systematically characterize the STPK complement of mycobacterium. Our analysis revealed that while Mycobacterium tuberculosis strains have 11 conserved kinases, this number varies from 4 to
more » ... er varies from 4 to 24 in other mycobacterial species. pknA, an essential STPK encoding gene, was found to be truncated in the initial analysis of M. avium subsp. paratuberculosis (Map) and M. tuberculosis C genomes. However, resequencing of pknA gene in Map confirmed that the truncation was due to a sequencing error. The conservation of division and cell wall gene cluster involved in cell envelope biosynthesis and cell division, in the vicinity of pknL locus, implicates a possible role of PknL in cell division and envelop biosynthesis. We identified a cyclophilin domain as part of a mycobacterial kinase in Map that suggests a plausible regulation of cyclophilins by phosphorylation. The co-inheritance of pknA, pknB, pknG, and pknL loci across genomes and some unique repertoire of pathogen-specific kinases such as pknI and pknJ of Mtb complex suggest similitude and divergence between pathogenic and nonpathogenic signaling. This study would add another dimension toward identification of physiological substrates and thereby function, while resolving the existing complexities in signaling network between the two domains of life, pathogen and nonpathogen. kinase; Mycobacterium; synteny; SymBet; comparative genomics THE GENUS MYCOBACTERIUM INCLUDES acid fast bacilli with more than 90 species, including slow-growing pathogens of Mycobacterium tuberculosis complex [M. tuberculosis (Mtb), M. bovis (Mbo), M. africanum, M. microti, and M. canettii], M. avium-intracellulare complex (M. intracellulare and M. avium), M. marinum (Mma), M. leprae (Mle), and nonpathogenic, fast-growing species such as M. smegmatis (Msm). Human tuberculosis is caused mainly by Mtb; however, the etiological agent of bovine tuberculosis, Mbo can also cause human disease. Two genetically distinct species within M. avium-intracellulare complex are M. avium, which tends to infect human immunodeficiency virus-infected patients, and M. intracellulare, more common among immunocompetent individuals (27). Unlike M. intracellulare, which relates to a single species, M. avium is separated into three subspecies; M. avium Article published online before print. See web site for date of publication
doi:10.1152/physiolgenomics.00221.2006 pmid:17148687 fatcat:ydudtlu4xrgaliug2eafvgafx4