Berg A, Vervoort J, de Kok A
Department of Biochemistry, Agricultural University, Wageningen, The Netherlands.
Eur J Biochem. 1997 Mar 1;244(2):352-60. doi: 10.1111/j.1432-1033.1997.00352.x.
The three-dimensional structure of the N-terminal lipoyl domain of the acetyltransferase component of the pyruvate dehydrogenase complex from Azotobacter vinelandii has been determined using heteronuclear multidimensional NMR spectroscopy and dynamical simulated annealing. The structure is compared with the solution structure of the lipoyl domain of the A. vinelandii 2-oxoglutarate dehydrogenase complex. The overall fold of the two structures, described as a beta-barrel-sandwich hybrid, is very similar. This agrees well with the high similarity of NMR-derived parameters, e.g. chemical shifts, between the two lipoyl domains. The main structural differences between the two lipoyl domains occur in a solvent-exposed loop close in space to the lipoylation site. Despite their high structural similarity, these lipoyl domains show a high preference for being reductively acylated by their parent 2-oxo acid dehydrogenase. Potential residues of the lipoyl domain involved in this process of molecular recognition are discussed.
利用异核多维核磁共振光谱和动力学模拟退火技术，确定了来自棕色固氮菌的丙酮酸脱氢酶复合体乙酰转移酶组分N端硫辛酰结构域的三维结构。将该结构与棕色固氮菌2-氧代戊二酸脱氢酶复合体硫辛酰结构域的溶液结构进行了比较。这两种结构的整体折叠形式被描述为β-桶三明治杂合体，非常相似。这与两种硫辛酰结构域之间核磁共振衍生参数（如化学位移）的高度相似性非常吻合。两种硫辛酰结构域的主要结构差异出现在空间上靠近硫辛酰化位点的一个溶剂暴露环中。尽管它们在结构上高度相似，但这些硫辛酰结构域对被其亲本2-氧代酸脱氢酶进行还原酰化表现出高度偏好。讨论了参与这一分子识别过程的硫辛酰结构域的潜在残基。
