Download MendeleyThe ligand-binding domain of a chemoreceptor from Comamonas testosteroni has a previously unknown homotrimeric structure.
Hong, Y., Huang, Z., Guo, L., Ni, B., Jiang, C.Y., Li, X.J., Hou, Y.J., Yang, W.S., Wang, D.C., Zhulin, I.B., Liu, S.J., Li, D.F.(2019) Mol Microbiol
- PubMed: 31177588
- DOI: https://doi.org/10.1111/mmi.14326
- Primary Citation of Related Structures:
5XUA, 5XUB, 6ITS - PubMed Abstract:
Transmembrane chemoreceptors are widely present in Bacteria and Archaea. They play a critical role in sensing various signals outside and transmitting to the cell interior. Here, we report the structure of the periplasmic ligand-binding domain (LBD) of the transmembrane chemoreceptor MCP2201, which governs chemotaxis to citrate and other organic compounds in Comamonas testosteroni. The apo-form LBD crystal revealed a typical four-helix bundle homodimer, similar to previously well-studied chemoreceptors such as Tar and Tsr of Escherichia coli. However, the citrate-bound LBD revealed a four-helix bundle homotrimer that had not been observed in bacterial chemoreceptor LBDs. This homotrimer was further confirmed with size-exclusion chromatography, analytical ultracentrifugation and cross-linking experiments. The physiological importance of the homotrimer for chemotaxis was demonstrated with site-directed mutations of key amino acid residues in C. testosteroni mutants.
Organizational Affiliation:
State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No. 1 Beichen West Road, Chaoyang District, Beijing, 100101, China.
