STAS Domain Structure and Function

Abstract

Pendrin shares with nearly all SLC26/SulP anion transporters a carboxy-terminal cytoplasmic segment organized around a Sulfate Transporter and Anti-Sigma factor antagonist (STAS) domain. STAS domains of divergent amino acid sequence exhibit a conserved fold of 4 β strands interspersed among 5 α helices. The first STAS domain proteins studied were single-domain anti-sigma factor antagonists (anti-anti-σ). These anti-anti-σ indirectly stimulate bacterial RNA polymerase by inactivating inhibitory anti-σ kinases, liberating σ factors to direct specific transcription of target genes or operons. Some STAS domains are nucleotide-binding phosphoproteins or nucleotidases. Others are interaction/transduction modules within multidomain sensors of light, oxygen and other gasotransmitters, cyclic nucleotides, inositol phosphates, and G proteins. Additional multidomain STAS protein sequences suggest functions in sensing, metabolism, or transport of nutrients such as sugars, amino acids, lipids, anions, vitamins, or hydrocarbons. Still other multidomain STAS polypeptides include histidine and serine/threonine kinase domains and ligand-activated transcription factor domains. SulP/SLC26 STAS domains and adjacent sequences interact with other transporters, cytoskeletal scaffolds, and with enzymes metabolizing transported anion substrates, forming putative metabolons. STAS domains are central to membrane targeting of many SulP/SLC26 anion transporters, and STAS domain mutations are associated with at least three human recessive diseases. This review summarizes STAS domain structure and function.

Screening of a Leptospira biflexa Mutant Library To Identify Genes Involved in Ethidium Bromide Tolerance

“…Activation of ECFs occurs through inactivation of anti-sigma factors by STAS (sulfate transporter and anti-sigma factor antagonists) (57). In our study, we identified two STAS anti-sigma factor antagonists, LEPBIa2328 and its paralogue LEPBIa0072 (Id ϭ 39.4%, Pos ϭ 65.7%) (31)(32)(33)58). The importance of LEPBIa2328 in tolerance to EtBr is supported by the fact that we identified two independent mutants in this gene.…”

GigA and GigB are Master Regulators of Antibiotic Resistance, Stress Responses, and Virulence in Acinetobacter baumannii

“…The GigB protein contains a sulfate transport and anti-sigma factor antagonist (STAS) domain. In several other bacterial species, TCS-RRs harboring PP2C domains and STAS domaincontaining anti-anti-sigma factors function together to regulate the activity of antisigma factors, effectively functioning to activate alternative sigma factors (26)(27)(28)(29)(30). The Bacillus subtilis sigma B ( B ) regulatory system represents a well-characterized example of such a signal transduction pathway.…”

The General Stress Response σS Is Regulated by a Partner Switch in the Gram-negative Bacterium Shewanella oneidensis

“…As described regarding other anti-sigma antagonists like RsbV from B. subtilis, SypA from V. fisheri, or HsbA from P. aeruginosa, CrsA contains the conserved STAS domain and a potentially phosphorylatable serine residue at position 49 ( Fig. 1A) (24,31,37,40). The second protein, CrsR (SO2119), is a 64-kDa protein that presents characteristics of an unusual response regulator.…”

“…In turn, the latter can thus associate with the RNA polymerase and can induce expression of its regulon. In this mechanism, the availability of the sigma factor depends on the phosphorylation state of the anti-sigma antagonist (30,31). Although partner-switching systems were initially unveiled in Gram-positive bacteria, they have also been found in some Gram-negative bacteria including Bordetella (BtrWVU), Vibrio fisheri (SypEA), and Pseudomonas aeruginosa (HsbRA).…”