1p51
Anabaena HU-DNA cocrystal structure (AHU6)Anabaena HU-DNA cocrystal structure (AHU6)
Structural highlights
FunctionDBH_NOSS1 Histone-like DNA-binding protein which is capable of wrapping DNA to stabilize it, and thus to prevent its denaturation under extreme environmental conditions. It is essential for heterocyst differentiation. 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 PubMedHU and IHF are members of a family of prokaryotic proteins that interact with the DNA minor groove in a sequence-specific (IHF) or non-specific (HU) manner to induce and/or stabilize DNA bending. HU plays architectural roles in replication initiation, transcription regulation and site-specific recombination, and is associated with bacterial nucleoids. Cocrystal structures of Anabaena HU bound to DNA (1P71, 1P78, 1P51) reveal that while underlying proline intercalation and asymmetric charge neutralization mechanisms of DNA bending are similar for IHF and HU, HU stabilizes different DNA bend angles ( approximately 105-140 degrees ). The two bend angles within a single HU complex are not coplanar, and the resulting dihedral angle is consistent with negative supercoiling. Comparison of HU-DNA and IHF-DNA structures suggests that sharper bending is correlated with longer DNA binding sites and smaller dihedral angles. An HU-induced bend may be better modeled as a hinge, not a rigid bend. The ability to induce or stabilize varying bend angles is consistent with HU's role as an architectural cofactor in many different systems that may require differing geometries. Flexible DNA bending in HU-DNA cocrystal structures.,Swinger KK, Lemberg KM, Zhang Y, Rice PA EMBO J. 2003 Jul 15;22(14):3749-60. PMID:12853489[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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