3FTC

Crystal structure of A. aeolicus KsgA at 1.72-Angstrom resolution

Summary for 3FTC

• Entry DOI: 10.2210/pdb3ftc/pdb
• Related: 1G38 1QYR 1ZQ9 3FTD 3FTE 3FTF
• Descriptor: Dimethyladenosine transferase (2 entities in total)
• Functional Keywords: ksga, rossmann-like fold, rna methyltransferase, mtase, antibiotic resistance, methyltransferase, rna-binding, rrna processing, s-adenosyl-l-methionine, transferase
• Biological source: Aquifex aeolicus
• Cellular location: Cytoplasm (Potential): O67680
• Total number of polymer chains: 1
• Total formula weight: 28484.35

Authors

Tu, C.,Ji, X. (deposition date: 2009-01-12, release date: 2009-03-24, Last modification date: 2024-11-20)

Primary citation

Tu, C.,Tropea, J.E.,Austin, B.P.,Court, D.L.,Waugh, D.S.,Ji, X.
Structural Basis for Binding of RNA and Cofactor by a KsgA Methyltransferase.
Structure, 17:374-385, 2009

PubMed Abstract: Among methyltransferases, KsgA and the reaction it catalyzes are conserved throughout evolution. However, the specifics of substrate recognition by the enzyme remain unknown. Here we report structures of Aquifex aeolicus KsgA, in its ligand-free form, in complex with RNA, and in complex with both RNA and S-adenosylhomocysteine (SAH, reaction product of cofactor S-adenosylmethionine), revealing critical structural information on KsgA-RNA and KsgA-SAH interactions. Moreover, the structures show how conformational changes that occur upon RNA binding create the cofactor-binding site. There are nine conserved functional motifs (motifs I-VIII and X) in KsgA. Prior to RNA binding, motifs I and VIII are flexible, each exhibiting two distinct conformations. Upon RNA binding, the two motifs become stabilized in one of these conformations, which is compatible with the binding of SAH. Motif X, which is also stabilized upon RNA binding, is directly involved in the binding of SAH.

PubMed: 19278652
DOI: 10.1016/j.str.2009.01.010

Experimental method

X-RAY DIFFRACTION (1.68 Å)