phosphoacceptor receiver (REC) domain of LytTR/AlgR family response regulators similar to AgrA
Members of the LytTR/AlgR family of response regulators contain a REC domain and a unique LytTR DNA-binding output domain that lacks the helix-turn-helix motif and consists mostly of beta-strands. Transcriptional regulators with the LytTR-type output domains are involved in biosynthesis of extracellular polysaccharides, fimbriation, expression of exoproteins, including toxins, and quorum sensing. Included in this AgrA-like group of LytTR/AlgR family response regulators are Staphylococcus aureus accessory gene regulator protein A (AgrA) and Streptococcus pneumoniae response regulator ComE, which are members of two-component regulatory systems. AgrA is a global regulator that controls the synthesis of virulence factors and other exoproteins. ComE is part of the ComD-ComE system that is part of a quorum-sensing signaling pathway that controls the development of competence, a physiological state required for genetic transformation. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.
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