Protein Family Models

helix-turn-helix domain-containing protein such as an XRE (Xenobiotic Response Element) family transcriptional regulator

Date:

2024-04-09

In Gram-positive bacteria, cell-to-cell communication mainly relies on extracellular signaling peptides. ComR is a member of the RNPP family, which positively controls competence for natural DNA transformation in streptococci. It is directly activated by the binding of its associated pheromone XIP [1]. The crystal structure analysis of ComR shows that it contains an N-terminal helix-turn-helix (HTH), DNA binding domain (DBD) and a C-terminal tetratricopeptide repeat (TPR) domain. The TPR domain is composed of 11 alpha-helices forming 5 TPR motifs followed by an additional C-terminal alpha-helix 16 called CAP. The pheromone XIP binding site is found in the TPR region. Biochemical and mutational analysis indicate that, if the interacting XIP is accepted it can then trigger the conformational change of the TPR domain to open the DBD-TPR interface to allow dimer formation that is required to bind DNA [2]. [1]. 27907189. Structural Insights into Streptococcal Competence Regulation by the Cell-to-Cell Communication System ComRS. Talagas A, Fontaine L, Ledesma-Garcia L, Mignolet J, Li de la Sierra-Gallay I, Lazar N, Aumont-Nicaise M, Federle MJ, Prehna G, Hols P, Nessler S;. PLoS Pathog. 2016;12:e1005980. [2]. 27907154. Pheromone Recognition and Selectivity by ComR Proteins among Streptococcus Species. Shanker E, Morrison DA, Talagas A, Nessler S, Federle MJ, Prehna G;. PLoS Pathog. 2016;12:e1005979. (from Pfam)

Date:

2024-10-16

This large family of DNA binding helix-turn helix proteins includes Cro Swiss:P03036 and CI Swiss:P03034. Within the protein Swiss:Q5F9C2, the full protein fold incorporates a helix-turn-helix motif, but the function of this member is unlikely to be that of a DNA-binding regulator, the function of most other members, so is not necessarily characteristic of the whole family [1]. [1]. 20196080. The crystal structure of NGO0477 from Neisseria gonorrhoeae reveals a novel protein fold incorporating a helix-turn-helix motif. Ren J, Sainsbury S, Nettleship JE, Saunders NJ, Owens RJ;. Proteins. 2010;78:1798-1802. (from Pfam)

Date:

2024-10-16

Rgg4, also called ComR, as found in Streptococcus pyogenes, is a transcriptional regulator paralogous to the quorum-sensing system pair Rgg2 and Rgg3.

Gene:

rgg4

Date:

2020-12-17