He Qing, Wang Kang, Su Tiantian, Wang Feng, Gu Lichuan, Xu Sujuan
State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, No. 27 Shanda South Road, Jinan, Shandong 250100, People's Republic of China.
Acta Crystallogr F Struct Biol Commun. 2017 Jul 1;73(Pt 7):431-436. doi: 10.1107/S2053230X17009025. Epub 2017 Jun 28.
VqsR is a quorum-sensing (QS) transcriptional regulator which controls QS systems (las, rhl and pqs) by directly downregulating the expression of qscR in Pseudomonas aeruginosa. As a member of the LuxR family of proteins, VqsR shares the common motif of a helix-turn-helix (HTH)-type DNA-binding domain at the C-terminus, while the function of its N-terminal domain remains obscure. Here, the crystal structure of the N-terminal domain of VqsR (VqsR-N; residues 1-193) was determined at a resolution of 2.1 Å. The structure is folded into a regular α-β-α sandwich topology, which is similar to the ligand-binding domain (LBD) of the LuxR-type QS receptors. Although their sequence similarity is very low, structural comparison reveals that VqsR-N has a conserved enclosed cavity which could recognize acyl-homoserine lactones (AHLs) as in other LuxR-type AHL receptors. The structure suggests that VqsR could be a potential AHL receptor.
VqsR是一种群体感应（QS）转录调节因子，它通过直接下调铜绿假单胞菌中qscR的表达来控制QS系统（las、rhl和pqs）。作为LuxR家族蛋白的一员，VqsR在C端共享螺旋-转角-螺旋（HTH）型DNA结合结构域的共同基序，而其N端结构域的功能仍不清楚。在此，VqsR的N端结构域（VqsR-N；第1至193位氨基酸残基）的晶体结构以2.1 Å的分辨率得以确定。该结构折叠成规则的α-β-α三明治拓扑结构，类似于LuxR型QS受体的配体结合结构域（LBD）。尽管它们的序列相似性非常低，但结构比较显示，VqsR-N有一个保守的封闭腔，如同其他LuxR型AHL受体一样，该腔可以识别酰基高丝氨酸内酯（AHLs）。该结构表明VqsR可能是一种潜在的AHL受体。
