7R65

Crystal structure of a bacterial cyclic UMP synthase from Burkholderia cepacia LK29

Summary for 7R65

• Entry DOI: 10.2210/pdb7r65/pdb
• Descriptor: Adenylate/guanylate cyclase (2 entities in total)
• Functional Keywords: cyclic nucleotide, nucleotidyltransferase, bacteriophage-defense, pycsar, transferase
• Biological source: Burkholderia cepacia (Pseudomonas cepacia)
• Total number of polymer chains: 4
• Total formula weight: 103078.06

Authors

Morehouse, B.R.,Kranzusch, P.J. (deposition date: 2021-06-22, release date: 2021-10-13, Last modification date: 2024-10-16)

Primary citation

Tal, N.,Morehouse, B.R.,Millman, A.,Stokar-Avihail, A.,Avraham, C.,Fedorenko, T.,Yirmiya, E.,Herbst, E.,Brandis, A.,Mehlman, T.,Oppenheimer-Shaanan, Y.,Keszei, A.F.A.,Shao, S.,Amitai, G.,Kranzusch, P.J.,Sorek, R.
Cyclic CMP and cyclic UMP mediate bacterial immunity against phages.
Cell, 184:5728-, 2021

PubMed Abstract: The cyclic pyrimidines 3',5'-cyclic cytidine monophosphate (cCMP) and 3',5'-cyclic uridine monophosphate (cUMP) have been reported in multiple organisms and cell types. As opposed to the cyclic nucleotides 3',5'-cyclic adenosine monophosphate (cAMP) and 3',5'-cyclic guanosine monophosphate (cGMP), which are second messenger molecules with well-established regulatory roles across all domains of life, the biological role of cyclic pyrimidines has remained unclear. Here we report that cCMP and cUMP are second messengers functioning in bacterial immunity against viruses. We discovered a family of bacterial pyrimidine cyclase enzymes that specifically synthesize cCMP and cUMP following phage infection and demonstrate that these molecules activate immune effectors that execute an antiviral response. A crystal structure of a uridylate cyclase enzyme from this family explains the molecular mechanism of selectivity for pyrimidines as cyclization substrates. Defense systems encoding pyrimidine cyclases, denoted here Pycsar (pyrimidine cyclase system for antiphage resistance), are widespread in prokaryotes. Our results assign clear biological function to cCMP and cUMP as immunity signaling molecules in bacteria.

PubMed: 34644530
DOI: 10.1016/j.cell.2021.09.031

Experimental method

X-RAY DIFFRACTION (1.45 Å)