Summary for 1XCB
| Entry DOI | 10.2210/pdb1xcb/pdb |
| Descriptor | Redox-sensing transcriptional repressor rex, CALCIUM ION, NICOTINAMIDE-ADENINE-DINUCLEOTIDE (3 entities in total) |
| Functional Keywords | redox-sensing, winged helix, rossmann fold, nicotinamide adenine dinucleotide, nad, rex, thermus aquaticus, new york sgx research center for structural genomics, nysgxrc, structural genomics, psi, protein structure initiative, dna binding protein |
| Biological source | Thermus aquaticus |
| Total number of polymer chains | 7 |
| Total formula weight | 168914.82 |
| Authors | Sickmier, E.A.,Brekasis, D.,Paranawithana, S.,Bonanno, J.B.,Burley, S.K.,Paget, M.S.,Kielkopf, C.L.,New York SGX Research Center for Structural Genomics (NYSGXRC) (deposition date: 2004-09-01, release date: 2004-09-28, Last modification date: 2021-02-03) |
| Primary citation | Sickmier, E.A.,Brekasis, D.,Paranawithana, S.,Bonanno, J.B.,Paget, M.S.,Burley, S.K.,Kielkopf, C.L. X-Ray Structure of a Rex-Family Repressor/NADH Complex: Insights into the Mechanism of Redox Sensing Structure, 13:43-54, 2005 Cited by PubMed Abstract: 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. PubMed: 15642260DOI: 10.1016/j.str.2004.10.012 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.9 Å) |
Structure validation
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