Protein Family Models

Bacillus subtilis respond to a multitude of environmental stimuli by using transcription factors called transition state regulators (TSRs). They play an essential role in cell survival by regulating spore formation, competence, and biofilm development. AbrB is one of the most known TSRs, acting as a pleotropic regulator for over 60 different genes where it directly binds to their promoter or regulatory regions. Many other genes are indirectly controlled by AbrB since it is a regulator of other regulatory proteins, including ScoC, Abh, SinR and SigH [1]. Hence, AbrB is considered a global regulatory protein controlling processes such as Bacillus subtilis growth and cell division as well as production of extracellular degradative enzymes, nitrogen utilization and amino acid metabolism, motility, synthesis of antibiotics and their resistant determinants, development of competence, transport systems, oxidative stress response, phosphate metabolism, cell surface components and sporulation [2]. AbrB is a tetramer consisting of identical 94 residue monomers. Its DNA-binding function resides solely in the N-terminal domain (AbrBN) of 53 residues [3]. Although it does not recognize a well-defined DNA base-pairing sequence, instead, it appears to target a very weak pseudo consensus nucleotide sequence, TGGNA-5bp-TGGNA, which allows it to be rather promiscuous in binding [1]. The N-terminal domains of very similar sequences are present in two more Bacillus subtilis proteins, Abh and SpoVT. Mutagenesis studies suggest that the role of the C-terminal domain is in forming multimers [4]. [1]. 19000822. Insights into the nature of DNA bin. TRUNCATED at 1650 bytes (from Pfam)

Date:

2024-08-14

AbrB family transcriptional regulator similar to Escherichia coli AbrB, also called AidB regulator or transition state regulatory protein AbrB, which seems to be involved in the regulation of AidB

Date:

2021-02-01

The model describes a hydrophobic sequence region that is duplicated to form the AbrB protein of Escherichia coli (not to be confused with a Bacillus subtilis protein with the same gene symbol). In some species, notably the Cyanobacteria and Thermus thermophilus, proteins consist of a single copy rather than two copies. The member from Pseudomonas putida, PP_1415, was suggested to be an ammonia monooxygenase characteristic of heterotrophic nitrifiers, based on an experimental indication of such activity in the organism and a glimmer of local sequence similarity between parts of P. putida protein and an instance of the AmoA protein from Nitrosomonas europaea (PMID:9732537); we do not believe the sequence similarity to be meaningful. The member from E. coli (b0715, ybgN) appears to be the largely uncharacterized AbrB (aidB regulator) protein of E. coli cited in Volkert, et al. (PMID 8002588), although we did not manage to trace the origin of association of the article to the sequence.

Date:

2019-09-10