Structural highlights
Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe cAMP responsive element-binding protein (CREB) is central to second messenger regulated transcription. To elucidate the structural mechanisms of DNA binding and selective dimerization of CREB, we determined to 3.0 A resolution, the structure of the CREB bZIP (residues 283-341) bound to a 21-base pair deoxynucleotide that encompasses the canonical 8-base pair somatostatin cAMP response element (SSCRE). The CREB dimer is stabilized in part by ionic interactions from Arg(314) to Glu(319') and Glu(328) to Lys(333') as well as a hydrogen bond network that links the carboxamide side chains of Gln(322')-Asn(321)-Asn(321')-Gln(322). Critical to family selective dimerization are intersubunit hydrogen bonds between basic region residue Tyr(307) and leucine zipper residue Glu(312), which are conserved in all CREB/CREM/ATF-1 family members. Strikingly, the structure reveals a hexahydrated Mg(2+) ion bound in the cavity between the basic region and SSCRE that makes a water-mediated DNA contact. DNA binding studies demonstrate that Mg(2+) ions enhance CREB bZIP:SSCRE binding by more than 25-fold and suggest a possible physiological role for this ion in somatostatin cAMP response element and potentially other CRE-mediated gene expression. The structure of a CREB bZIP.somatostatin CRE complex reveals the basis for selective dimerization and divalent cation-enhanced DNA binding.,Schumacher MA, Goodman RH, Brennan RG J Biol Chem. 2000 Nov 10;275(45):35242-7. PMID:10952992[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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