Probing the nucleotide binding and phosphorylation by the histidine kinase of a novel three-protein two-component system from Mycobacterium tuberculosis.
FEBS Lett
; 581(9): 1903-9, 2007 May 01.
Article
em En
| MEDLINE
| ID: mdl-17434492
ABSTRACT
The two-component signal transduction system from Mycobacterium tuberculosis bears a unique three-protein system comprising of two putative histidine kinases (HK1 and HK2) and one response regulator TcrA. By sequence analysis, HK1 is found to be an adenosine 5'-triphosphate (ATP) binding protein, similar to the nucleotide-binding domain of homologous histidine kinases, and HK2 is a unique histidine containing phosphotransfer (HPt)-mono-domain protein. HK1 is expected to interact with and phosphorylate HK2. Here, we show that HK1 binds 2'(3')-O-(2,4,6-trinitrophenyl)adenosine 5'-triphosphate monolithium trisodium salt and ATP with a 11 stoichiometric ratio. The ATPase activity of HK1 in the presence of HK2 was measured, and phosphorylation experiments suggested that HK1 acts as a functional kinase and phosphorylates HK2 by interacting with it. Further phosphorylation studies showed transfer of a phosphoryl group from HK2 to the response regulator TcrA. These results indicate a new mode of interaction for phosphotransfer between the two-component system proteins in bacteria.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas Quinases
/
Mycobacterium tuberculosis
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article