6y4b

Publication Abstract from PubMed

Cyclodipeptide synthases (CDPSs) catalyze the synthesis of various cyclodipeptides by using two aminoacyl-tRNA (aa-tRNA) substrates in a sequential mechanism. Here, we studied binding of phenylalanyl-tRNA(Phe) to the CDPS from Candidatus Glomeribacter gigasporarum (Cglo-CDPS) by gel filtration and electrophoretic mobility shift assay. We determined the crystal structure of the Cglo-CDPS:Phe-tRNA(Phe) complex to 5 A resolution and further studied it in solution using small-angle X-ray scattering (SAXS). The data show that the major groove of the acceptor stem of the aa-tRNA interacts with the enzyme through the basic beta2 and beta7 strands of CDPSs belonging to the XYP subfamily. A bending of the CCA extremity enables the amino acid moiety to be positioned in the P1 pocket while the terminal A76 adenosine occupies the P2 pocket. Such a positioning indicates that the present structure illustrates the binding of the first aa-tRNA. In cells, CDPSs and the elongation factor EF-Tu share aminoacylated tRNAs as substrates. The present study shows that CDPSs and EF-Tu interact with opposite sides of tRNA. This may explain how CDPSs hijack aa-tRNAs from canonical ribosomal protein synthesis.

Structural basis of the interaction between cyclodipeptide synthases and aminoacylated tRNA substrates.,Bourgeois G, Seguin J, Babin M, Gondry M, Mechulam Y, Schmitt E RNA. 2020 Nov;26(11):1589-1602. doi: 10.1261/rna.075184.120. Epub 2020 Jul 17. PMID:32680846^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.