1xcb is a 7 chain structure with sequence from Thermus aquaticus. This structure supersedes the now removed PDB entry 1r72. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The redox-sensing repressor Rex regulates transcription of respiratory genes in response to the intra cellular NADH/NAD(+) redox poise. As a step toward elucidating the molecular mechanism of NADH/NAD(+) sensing, the X-ray structure of Thermus aquaticus Rex (T-Rex) bound to effector NADH has been determined at 2.9 A resolution. The fold of the C-terminal domain of T-Rex is characteristic of NAD(H)-dependent enzymes, whereas the N-terminal domain is similar to a winged helix DNA binding motif. T-Rex dimerization is primarily mediated by "domain-swapped" alpha helices. Each NADH molecule binds to the C-terminal domain near the dimer interface. In contrast to NAD(H)-dependent enzymes, the nicotinamide is deeply buried within a hydrophobic pocket that appears to preclude substrate entry. We show that T-Rex binds to the Rex operator, and NADH but not NAD(+) inhibits T-Rex/DNA binding activity. A mechanism for redox sensing by Rex family members is proposed by analogy with domain closure of NAD(H)-dependent enzymes.
X-ray structure of a Rex-family repressor/NADH complex insights into the mechanism of redox sensing.,Sickmier EA, Brekasis D, Paranawithana S, Bonanno JB, Paget MS, Burley SK, Kielkopf CL Structure. 2005 Jan;13(1):43-54. PMID:15642260[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
↑Sickmier EA, Brekasis D, Paranawithana S, Bonanno JB, Paget MS, Burley SK, Kielkopf CL. X-ray structure of a Rex-family repressor/NADH complex insights into the mechanism of redox sensing. Structure. 2005 Jan;13(1):43-54. PMID:15642260 doi:https://dx.doi.org/10.1016/j.str.2004.10.012
