Protein Family Models

The chemoreceptor zinc-binding domain (CZB) is found in bacterial signal transduction proteins - most frequently receptors involved in chemotaxis and motility, but also in c-di-GMP signalling and nitrate/nitrite-sensing. Originally discovered in the cytoplasmic chemoreceptor TlpD from Helicobacter pylori, it is often found C-terminal to the MCPsignal domain in cytoplasmic chemoreceptor proteins. The CZB domain contains a core sequence motif, Hxx[WFYL]x21-28Cx[LFMVI]Gx[WFLVI]x18-27HxxxH. The highly-conserved H-C-H-H residues of this motif are believed to coordinate zinc; mutating the latter two histidines of the motif to alanines abolishes Zn binding. This domain binds zinc with high affinity, with a Kd in the femtomolar range. This domain has been shown in E. coli to be a zinc sensor that regulates the catalytic activity of Pfam:PF00990 [2]. This domain also binds the chemoattractant HOCl at a site very close to that of zinc. It has been shown that zinc participates in HOCl sensing by forming a redox 'Cys-Zn switch' that reacts towards HOCl (Matilla et. al.,FEMS Microbiology Reviews, fuab043, 45, 2021, 1. https://doi.org/10.1093/femsre/fuab043). [1]. 21725005. Identification of a chemoreceptor zinc-binding domain common to cytoplasmic bacterial chemoreceptors. Draper J, Karplus K, Ottemann KM;. J Bacteriol. 2011;193:4338-4345. [2]. 23769666. Structure and signaling mechanism of a zinc-sensory diguanylate cyclase. Zahringer F, Lacanna E, Jenal U, Schirmer T, Boehm A;. Structure. 2013;21:1149-1157. (from Pfam)

Date:

2024-10-16

This domain is found linked to a wide range of non-homologous domains in a variety of bacteria. It has been shown to be homologous to the adenylyl cyclase catalytic domain [1] and has diguanylate cyclase activity [4]. This observation correlates with the functional information available on two GGDEF-containing proteins, namely diguanylate cyclase and phosphodiesterase A of Acetobacter xylinum, both of which regulate the turnover of cyclic diguanosine monophosphate. In the WspR protein of Pseudomonas aeruginosa, the GGDEF domain acts as a diguanylate cyclase, PDB:3bre, when the whole molecule appears to form a tetramer consisting of two symmetrically-related dimers representing a biological unit. The active site is the GGD/EF motif, buried in the structure, and the cyclic dimeric guanosine monophosphate (c-di-GMP) bind to the inhibitory-motif RxxD on the surface. The enzyme thus catalyses the cyclisation of two guanosine triphosphate (GTP) molecules to one c-di-GMP molecule [6,7,8]. [1]. 11119645. GGDEF domain is homologous to adenylyl cyclase. Pei J, Grishin NV;. Proteins 2001;42:210-216. [2]. 11557134. Novel domains of the prokaryotic two-component signal transduction systems. Galperin MY, Nikolskaya AN, Koonin EV;. FEMS Microbiol Lett 2001;203:11-21. [3]. 15063857. Cyclic di-guanosine-monophosphate comes of age: a novel secondary messenger involved in modulating cell surface structures in bacteria?. Jenal U;. Curr Opin Microbiol 2004;7:185-191. [4]. 15075296. Cell cycle-dependent dynamic localization of a bacterial response regulator with a novel di-guanylate cyclase output domain. Paul R, Weiser S, Amiot NC, Chan C, Sch. TRUNCATED at 1650 bytes (from Pfam)

Date:

2024-10-16

sensor domain-containing diguanylate cyclase (GGDEF) contains a CZB (chemoreceptor zinc-binding) zinc sensor domain

Date:

2019-03-11

Gene:

dgcZ

Date:

2019-01-03

Date:

2020-10-26

The GGDEF domain is named for the motif GG[DE]EF shared by many proteins carrying the domain. There is evidence that the domain has diguanylate cyclase activity [1][3]. Several proteins carrying this domain also carry domains with functions relating to environmental sensing. These include PleD, a response regulator protein involved in the swarmer-to-stalked cell transition in Caulobacter crescentus[2], and FixL, a heme-containing oxygen sensor protein.

Date:

2021-04-27