title: Structure of ribonuclease H phased at 2 A resolution by MAD analysis of the selenomethionyl protein.
abstract: Ribonuclease H digests the RNA strand of duplex RNA.DNA hybrids into oligonucleotides. This activity is indispensable for retroviral infection and is involved in bacterial replication. The ribonuclease H from Escherichia coli is homologous with the retroviral proteins. The crystal structure of the E. coli enzyme reveals a distinctive alpha-beta tertiary fold. Analysis of the molecular model implicates a carboxyl triad in the catalytic mechanism and suggests a likely mode for the binding of RNA.DNA substrates. The structure was determined by the method of multiwavelength anomalous diffraction (MAD) with the use of synchrotron data from a crystal of the recombinant selenomethionyl protein.
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032.
authors.forename: W
authors.initials: W
authors.lastname: Yang
authors.forename: W A
authors.initials: WA
authors.lastname: Hendrickson
authors.forename: R J
authors.initials: RJ
authors.lastname: Crouch
authors.forename: Y
authors.initials: Y
authors.lastname: Satow
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D003196:Computer Graphics; D004722:Endoribonucleases / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011994:Recombinant Proteins; D016914:Ribonuclease H; D012643:Selenium; D012645:Selenomethionine; D012689:Sequence Homology, Nucleic Acid; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D011994:Recombinant Proteins; D012645:Selenomethionine; D004722:Endoribonucleases; D016914:Ribonuclease H; D012643:Selenium