Eppink M H, Schreuder H A, Van Berkel W J
Department of Biochemistry, Agricultural University, Wageningen, The Netherlands.
Protein Sci. 1997 Nov;6(11):2454-8. doi: 10.1002/pro.5560061119.
A novel conserved sequence motif has been located among the flavoprotein hydroxylases. Based on the crystal structure and site-directed mutagenesis studies of p-hydroxybenzoate hydroxylase (PHBH) from Pseudomonas fluorescens, this amino acid fingerprint sequence is proposed to play a dual function in both FAD and NAD(P)H binding. In PHBH, the novel sequence motif (residues 153-166) includes strand A4 and the N-terminal part of helix H7. The conserved amino acids Asp 159, Gly 160, and Arg 166 are necessary for maintaining the structure. The backbone oxygen of Cys 158 and backbone nitrogens of Gly 160 and Phe 161 interact indirectly with the pyrophosphate moiety of FAD, whereas it is known from mutagenesis studies that the side chain of the moderately conserved His 162 is involved in NADPH binding.
在黄素蛋白羟化酶中发现了一种新的保守序列基序。基于荧光假单胞菌对羟基苯甲酸羟化酶（PHBH）的晶体结构和定点诱变研究，该氨基酸指纹序列被认为在FAD和NAD(P)H结合中发挥双重功能。在PHBH中，新的序列基序（第153 - 166位残基）包括A4链和H7螺旋的N端部分。保守氨基酸天冬氨酸159、甘氨酸160和精氨酸166对于维持结构是必需的。半胱氨酸158的主链氧以及甘氨酸160和苯丙氨酸161的主链氮与FAD的焦磷酸部分间接相互作用，而从诱变研究可知，中度保守的组氨酸162的侧链参与NADPH结合。
