Teplyakov A, Obmolova G, Wilson K, Kuromizu K
EMBL, c/o DESY, Hamburg, Germany.
Eur J Biochem. 1993 Apr 15;213(2):737-41. doi: 10.1111/j.1432-1033.1993.tb17814.x.
The three-dimensional structure of apo-neocarzinostatin, an antitumour antibiotic protein isolated from Streptomyces carzinostaticus, has been determined by X-ray diffraction at 0.15-nm resolution and refined to R = 17.2%. The crystal structure of neocarzinostatin is similar to that of the related proteins actinoxanthin and macromomycin. It is also in good agreement with the solution structure determined by NMR spectroscopy. The protein molecule consists of a seven-stranded antiparallel beta-sandwich and a smaller lobe formed by two beta-ribbons. A deep cleft between the two lobes is a putative chromophore binding site. Side chains of Trp39, Leu45, Phe52, Phe78 and the disulphide Cys37-Cys47 aligning the binding cleft in neocarzinostatin suggest the importance of hydrophobic interactions in stabilizing the chromophore molecule. Comparison of the atomic models of neocarzinostatin, actinoxanthin and macromomycin reveals functional residues which might determine specificity towards different chromophores.
从制癌链霉菌中分离得到的抗肿瘤抗生素蛋白脱辅基新制癌菌素的三维结构已通过0.15纳米分辨率的X射线衍射测定，并精修至R值为17.2%。新制癌菌素的晶体结构与相关蛋白抗坏血黄素和巨霉素的晶体结构相似。它也与通过核磁共振光谱法测定的溶液结构高度吻合。该蛋白质分子由一个七股反平行β折叠三明治结构和一个由两条β折叠带形成的较小叶组成。两个叶之间的深裂缝是一个假定的发色团结合位点。新制癌菌素中排列结合裂缝的色氨酸39、亮氨酸45、苯丙氨酸52、苯丙氨酸78的侧链以及二硫键半胱氨酸37 - 半胱氨酸47表明疏水相互作用在稳定发色团分子中的重要性。新制癌菌素、抗坏血黄素和巨霉素的原子模型比较揭示了可能决定对不同发色团特异性的功能残基。
