title: An isomorphous heavy-atom derivative of crystaline formylmethionine transfer RNA.
abstract: An isomorphous osmium derivative of crystalline yeast initiator transfer RNA has been prepared and interpreted to 6-angstrom resolution. The coordinates of the heavy atoms have been determined by Patterson and "direct" methods applied to the difference coefficients of the centric projections, followed by least-squares refinement. There is one dominant site per asymmetric unit, consistent with the finding by neutron-activation analysis that there is approximately one osmium atom per molecule of transfer RNA. The osmium derivative appears to be a normal substrate for enzymatic aminoacylation.
mesh_terms: D000201:Activation Analysis; D000215:Acylation; D001665:Binding Sites; D003461:Crystallography; D005561:Formates / Q000138:chemical synthesis; D008715:Methionine / Q000138:chemical synthesis*; D009992:Osmium; D012343:RNA, Transfer / Q000138:chemical synthesis*; D012440:Saccharomyces; D013329:Structure-Activity Relationship
chemical_list: D005561:Formates; D009992:Osmium; D012343:RNA, Transfer; D008715:Methionine