Crystal structure of the chemotaxis receptor methyltransferase CheR suggests a conserved structural motif for binding S-adenosylmethionine.
Djordjevic, S., Stock, A.M.(1997) Structure 5: 545-558
- PubMed: 9115443 
- DOI: https://doi.org/10.1016/s0969-2126(97)00210-4
- Primary Citation of Related Structures:  
1AF7 - PubMed Abstract: 
Flagellated bacteria swim towards favorable chemicals and away from deleterious ones. The sensing of chemoeffector gradients involves chemotaxis receptors, transmembrane proteins that detect stimuli through their periplasmic domains and transduce signals via their cytoplasmic domains to the downstream signaling components. Signaling outputs from chemotaxis receptors are influenced both by the binding of the chemoeffector ligand to the periplasmic domain and by methylation of specific glutamate residues on the cytoplasmic domain of the receptor. Methylation is catalyzed by CheR, an S-adenosylmethionine-dependent methyltransferase. CheR forms a tight complex with the receptor by binding a region of the receptors that is distinct from the methylation site. CheR belongs to a broad class of enzymes involved in the methylation of a variety of substrates. Until now, no structure from the class of protein methyltransferases has been characterized.
Organizational Affiliation: 
Howard Hughes Medical, Institute Center for Advanced Biotechnology and Medicine, Department of Biochemistry, University of Medicine and Dentistry of New Jersey, Piscataway, New Jersey, 08854, USA.