Kort R, Phillips-Jones M K, van Aalten D M, Haker A, Hoffer S M, Hellingwerf K J, Crielaard W
Laboratory for Microbiology, EC Slater Institute, University of Amsterdam, Nieuwe Achtergracht 127, 1018 WS Amsterdam, Netherlands.
Biochim Biophys Acta. 1998 Jun 11;1385(1):1-6. doi: 10.1016/s0167-4838(98)00050-8.
The photoactive yellow protein (pyp) gene has been isolated from Rhodobacter sphaeroides by probing with a homologous PCR-product. A sequence analysis shows that this pyp gene encodes a 124 AA protein with 48% identity to the three known PYPs. Downstream from pyp, a number of adjacent open reading frames were identified, including a gene encoding a CoA-ligase homologue (pCL). This latter protein is proposed to be involved in PYP chromophore activation, required for attachment to the apoprotein. We have demonstrated the presence of the chromophoric group, previously identified in PYP from Ectothiorhodospira halophila as trans 4-hydroxy cinnamic acid, in phototrophically cultured R. sphaeroides cells by capillary zone electrophoresis. The basic structure of the chromophore binding pocket in PYP has been conserved, as shown by a 3D model of R. sphaeroides PYP, constructed by homology-based molecular modelling. In addition, this model shows that R. sphaeroides PYP contains a characteristic, positively charged patch.
通过用同源PCR产物进行探测，已从球形红杆菌中分离出光敏黄色蛋白（pyp）基因。序列分析表明，该pyp基因编码一种124个氨基酸的蛋白质，与三种已知的PYP有48%的同一性。在pyp下游，鉴定出了一些相邻的开放阅读框，包括一个编码辅酶A连接酶同源物（pCL）的基因。推测后一种蛋白质参与PYP发色团的激活，这是其与脱辅基蛋白结合所必需的。我们通过毛细管区带电泳证明了在光养培养的球形红杆菌细胞中存在发色基团，该发色基团先前在嗜盐外硫红螺菌的PYP中被鉴定为反式4-羟基肉桂酸。通过基于同源性的分子建模构建的球形红杆菌PYP的三维模型表明，PYP中发色团结合口袋的基本结构是保守的。此外，该模型表明球形红杆菌PYP含有一个特征性的带正电荷区域。
