PRIMARY STRUCTURE AND FUNCTIONAL-ANALYSIS OF THE SOLUBLE TRANSDUCER PROTEIN HTRXI IN THE ARCHAEON HALOBACTERIUM-SALINARIUM

Citation
A. Brooun et al., PRIMARY STRUCTURE AND FUNCTIONAL-ANALYSIS OF THE SOLUBLE TRANSDUCER PROTEIN HTRXI IN THE ARCHAEON HALOBACTERIUM-SALINARIUM, Journal of bacteriology, 179(9), 1997, pp. 2963-2968
Citations number
26
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Microbiology
Journal title
ISSN journal
0021-9193
Volume
179
Issue
9
Year of publication
1997
Pages
2963 - 2968
Database
ISI
SICI code
0021-9193(1997)179:9<2963:PSAFOT>2.0.ZU;2-9
Abstract
Signal transduction in the archaeon Halobacterium salinarium is mediat ed by a family of 13 soluble and membrane-bound transducers. Here, we report the primary structure and functional analysis of one of the sma llest halobacterial putative transducers, HtrXI, Hydropathy plot analy sis of the primary structure predicts no membrane-spanning segments in HtrXI, The fractionation of the H, salinarium proteins confirmed that HtrXI is a soluble protein. Capillary assay with an HtrXI deletion mu tant and a complemented strain revealed that this soluble transducer i s involved in Asp and Glu taxis, In vivo analysis of the methylesteras e activity of the htrXI-1 deletion mutant suggests that HtrXI plays an important role in the adaptation of the chemotactic responses to His, Asp, and Glu, which are attractants for halobacteria, Stimulation by Asp and Glu causes demethylation of HtrXI and of another putative tran sducer, HtrVII, But addition of His to halobacterial cells increases H trXI methylation together with that of other putative transducers. In the absence of HtrXI, stimulation by either Glu or His does not decrea se or increase the methylation of any putative transducers. Therefore, the HtrXI transducer appears to have a complex role in chemotaxis sig nal transduction.