1XCB

X-ray Structure of a Rex-Family Repressor/NADH Complex from Thermus Aquaticus

「1R72」から置き換えられました

1XCB の概要

• エントリーDOI: 10.2210/pdb1xcb/pdb
• 分子名称: Redox-sensing transcriptional repressor rex, CALCIUM ION, NICOTINAMIDE-ADENINE-DINUCLEOTIDE (3 entities in total)
• 機能のキーワード: 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
• 由来する生物種: Thermus aquaticus
• タンパク質・核酸の鎖数: 7
• 化学式量合計: 168914.82

構造登録者

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) (登録日: 2004-09-01, 公開日: 2004-09-28, 最終更新日: 2021-02-03)

主引用文献

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

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: 15642260
DOI: 10.1016/j.str.2004.10.012

実験手法

X-RAY DIFFRACTION (2.9 Å)