Abstract:
:The involvement of methylation in the chemosensory response of bacteria to many attractants has been clearly established by studies in several laboratories. It has been assumed that adaptation of Salmonella typhimurium and Escherichia coli to all attractants involves methylation of a transmembrane methyl-accepting chemotaxis protein. The methyl donor in this reaction is S-adenosyl-L-methionine, and the protein methyltransferase is the product of the cheR gene. In contrast, adaptation to oxygen and phosphotransferase substrates were found to be independent of this methylation system. In E. coli AW660 (tsr tar trg), which lacks the known methyl-accepting chemotaxis proteins, chemotaxis was normal to oxygen and to substrates of the phosphotransferase system such as D-mannose, D-glucose, and N-acetyl-D-glucosamine. When S-adenosyl-L-methionine was depleted by methionine starvation or by addition of 1-aminocyclopentane-1-carboxylic acid, methylation-dependent adaptation to serine, aspartate, and ribose was defective in wild-type E. coli and S. typhimurium. However, adaptation to oxygen and phosphotransferase substrates was independent of S-adenosyl-L-methionine and the cheR product. These results suggest that there are methylation-independent and methylation-dependent mechanisms for sensory adaptation in bacteria.
journal_name
Proc Natl Acad Sci U S Aauthors
Niwano M,Taylor BLdoi
10.1073/pnas.79.1.11subject
Has Abstractpub_date
1982-01-01 00:00:00pages
11-5issue
1eissn
0027-8424issn
1091-6490journal_volume
79pub_type
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