Protein Family Models

The HBM sensor domain has been identified primarily in bacterial chemoreceptors but is also present on histidine kinases. Characteristic features of this domain are its size of approximately 250 amino acids and its location in the bacterial periplasm [1]. The McpS chemoreceptor of Pseudomonas putida KT2440 was found to possess an HBM sensor domain and its 3D structure in complex with physiologically relevant ligands has been reported [2]. This domain is composed of 2 long and 4 short helices that form two modules each composed of a 4-helix bundle. The McpS chemoreceptor mediates chemotaxis towards a number of organic acids [1,3]. Both modules of the McpS HBM domain contain a ligand binding site. Chemo-attractants binds to each of these sites and their binding was shown to trigger a chemotactic response [4]. This domain is primarily found in different proteobacteria but also in archaea. Interestingly, amino acids in both ligand binding sites showed a high degree of conservation suggesting that members of this family sense similar ligands. This domain recognises Multiple TCA cycle intermediates, citrate and alpha-ketoglutarate (Matilla et.al., FEMS Microbiology Reviews, fuab043, 45, 2021, 1. https://doi.org/10.1093/femsre/fuab043). [1]. 20498372. Identification of a chemoreceptor for tricarboxylic acid cycle intermediates: differential chemotactic response towards receptor ligands. Lacal J, Alfonso C, Liu X, Parales RE, Morel B, Conejero-Lara F, Rivas G, Duque E, Ramos JL, Krell T;. J Biol Chem. 2010;285:23126-23136. [2]. 21360620. Physiologically relevant divalent cations modulate citrate recognition by the McpS chemorecept. TRUNCATED at 1650 bytes (from Pfam)

Date:

2024-10-16

Date:

2024-08-14

This domain is thought to transduce the signal to CheA since it is highly conserved in very diverse MCPs. [1]. 1601874. Sequence and characterization of Bacillus subtilis CheW. Hanlon DW, Marquez-Magana LM, Carpenter PB, Chamberlin MJ, Ordal GW;. J Biol Chem 1992;267:12055-12060. (from Pfam)

Date:

2024-10-16

methyl-accepting chemotaxis protein (MCP) is a bacterial receptor that mediates chemotaxis to diverse signals, responding to changes in the concentration of attractants and repellents in the environment by altering swimming behavior

Date:

2024-04-06