ニシヤマ　ソウイチロウ   Soichiro Nishiyama   西山　宗一郎    所属   新潟薬科大学  応用生命科学部 応用生命科学科    職種   准教授
言語種別	英語
発行・発表の年月	1998/04
形態種別	論文
標題	Chemotactic adaptation is altered by changes in the carboxy-terminal sequence conserved among the major methyl-accepting chemoreceptors.
執筆形態	共著
掲載誌名	Journal of bacteriology
掲載区分	国外
巻・号・頁	180(7),pp.1862-8
著者・共著者	Okumura H, Nishiyama S, Sasaki A, Homma M, Kawagishi I
概要	In Escherichia coli and Salmonella typhimurium, methylation and demethylation of receptors are responsible for chemotactic adaptation and are catalyzed by the methyltransferase CheR and the methylesterase CheB, respectively. Among the chemoreceptors of these species, Tsr, Tar, and Tcp have a well-conserved carboxy-terminal motif (NWET/SF) that is absent in Trg and Tap. When they are expressed as sole chemoreceptors, Tsr, Tar, and Tcp support good adaptation, but Trg and Tap are poorly methylated and supported only weak adaptation. In this study, we characterized mutant receptors in which this pentapeptide sequence was altered. The adaptation abilities of C-terminally-mutated Tar and Tcp were severely impaired. Accordingly, the methylation levels of the mutant receptors increased only slightly upon addition of attractants. These results suggest that the pentapeptide sequence facilitates effective adaptation and methylation by recruiting CheR.
ISSN	0021-9193
PMID	9537386