Janowski Robert, Kefala Georgia, Weiss Manfred S
EMBL Hamburg Outstation, c/o DESY, Notkestrasse 85, D-22603 Hamburg, Germany.
Acta Crystallogr D Biol Crystallogr. 2010 Jan;66(Pt 1):61-72. doi: 10.1107/S0907444909043960. Epub 2009 Dec 21.
Dihydrodipicolinate reductase (DHDPR, DapB) is an enzyme that belongs to the L-lysine biosynthetic pathway. DHDPR reduces the alpha,beta-unsaturated cyclic imine 2,3-dihydrodipicolinic acid to yield the compound 2,3,4,5-tetrahydrodipicolinic acid in a pyridine nucleotide-dependent reaction. The substrate of this reaction is the unstable product of the preceding enzyme dihydrodipicolinate synthase (DHDPS, DapA). Here, the structure of apo-DHDPR from Mycobacterium tuberculosis is reported in two orthorhombic crystal forms, as well as the structure of DHDPR from M. tuberculosis in complex with NADH in a monoclinic crystal form. A comparison of the results with previously solved structures of this enzyme shows that DHDPR undergoes a major conformational change upon binding of its cofactor. This conformational change can be interpreted as one of the low-frequency normal modes of the structure.
二氢二吡啶甲酸还原酶（DHDPR，DapB）是一种属于L-赖氨酸生物合成途径的酶。DHDPR在依赖吡啶核苷酸的反应中，将α，β-不饱和环状亚胺2,3-二氢二吡啶甲酸还原，生成化合物2,3,4,5-四氢二吡啶甲酸。该反应的底物是前一种酶二氢二吡啶甲酸合酶（DHDPS，DapA）的不稳定产物。在此，报道了结核分枝杆菌无辅因子DHDPR的两种正交晶体形式的结构，以及结核分枝杆菌DHDPR与NADH复合物的单斜晶体形式的结构。将结果与该酶先前解析的结构进行比较表明，DHDPR在结合其辅因子后会发生重大构象变化。这种构象变化可被解释为该结构的低频正常模式之一。
