HTH_AsnC-type |
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PFAM accession number: | PF13404 |
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Interpro abstract (IPR000485): | The asnC-type HTH domain is a DNA-binding, helix-turn-helix (HTH) domain of about 60 amino acids present in transcription regulators of the asnC/lrp family. This family of prokaryotic regulators is named after Escherichia coli asnC and Leucine-responsive Regulatory Protein (lrp), which are a regulator of asparagine synthesis and a global regulator of various operons, respectively [ (PUBMED:2040596) ]. AsnC/lrp-like proteins are present in bacteria and archaea [ (PUBMED:7770911) ]. The DNA-binding asnC-type HTH domain occurs usually in the N-terminal part. The C-terminal part can contain an effector-binding domain and/or an oligomerisation domain. The crystal structure of hyperthermophilic archaeal lrpA shows that the N-terminal, DNA binding domain contains a core of three alpha-helices, followed by a single beta-strand, which connects as a flexible hinge to the effector binding domain. The second and third helices, connected via a turn, comprise the helix-turn-helix motif. Helix 3 is termed the recognition helix as it binds the DNA major groove, like in other HTHs. Most E. coli lrp DNA binding mutants are positioned in the lrpA structure on the HTH and three are on the hinge [ (PUBMED:11230123) ]. Proteins known to contain an asnC-type HTH domain include:
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GO function: | sequence-specific DNA binding (GO:0043565) |
This is a PFAM domain. For full annotation and more information, please see the PFAM entry HTH_AsnC-type