Ramelot Theresa A, Yee Adelinda, Cort John R, Semesi Anthony, Arrowsmith Cheryl H, Kennedy Michael A
Pacific Northwest National Laboratory, Biological Sciences Division, Richland, Washington 99354, USA.
Proteins. 2007 Feb 1;66(2):266-71. doi: 10.1002/prot.21199.
PA4608 is a 125 residue protein from Pseudomonas aeruginosa with a recent identification as a PilZ domain and putative bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) adaptor protein that plays a role in bacterial second-messenger regulated processes. The nuclear magnetic resonance (NMR) structure of PA4608 has been determined and c-di-GMP binding has been confirmed by NMR titration studies. The monomeric core structure of PA4608 contains a six-stranded anti-parallel beta barrel flanked by three helices. Conserved surface residues among PA4608 homologs suggest the c-di-GMP binding site is at one end of the barrel and includes residues in the helices as well as in the unstructured N-terminus. Chemical shift changes in PA4608 resonances upon titration with c-di-GMP confirm binding. This evidence supports the hypothesis that proteins containing PilZ domains are the long-sought c-di-GMP adaptor proteins.
PA4608是一种来自铜绿假单胞菌的由125个氨基酸残基组成的蛋白质，最近被鉴定为具有PilZ结构域以及假定的双（3'-5'）-环二聚鸟苷单磷酸（c-di-GMP）衔接蛋白，它在细菌第二信使调节过程中发挥作用。已确定PA4608的核磁共振（NMR）结构，并通过NMR滴定研究证实了c-di-GMP的结合。PA4608的单体核心结构包含一个由三条螺旋包围的六链反平行β桶。PA4608同源物中保守的表面残基表明，c-di-GMP结合位点位于桶的一端，包括螺旋以及无结构N端的残基。用c-di-GMP滴定后PA4608共振的化学位移变化证实了结合。这一证据支持了含有PilZ结构域的蛋白质是长期以来寻找的c-di-GMP衔接蛋白这一假设。
