Three-dimensional structure of ribonuclease H from E. coli.
The three-dimensional structure of RNase H from Escherichia coli was determined at 1.8 A resolution by X-ray crystallography. The enzyme was found to belong to the alpha + beta class of structures, consisting of two distinct domains. The structure implies a possible region interacting with a DNA-RNA hybrid. The Mg2(+)-binding site essential for activity is located near a cluster of four acidic amino acids--one glutamic and three aspartic acid residues. These residues are completely conserved in the homology alignment of sequences of RNase H and reverse transcriptases from retroviruses and retrovirus-like entities. The structural motif of beta strands around the Mg2(+)-binding site has similarities to that in DNase I.
Protein Engineering Research Institute, Osaka, Japan.
K
K
Katayanagi
M
M
Miyagawa
M
M
Matsushima
M
M
Ishikawa
S
S
Kanaya
M
M
Ikehara
T
T
Matsuzaki
K
K
Morikawa
D000595:Amino Acid Sequence; D001464:Barium / Q000378:metabolism / Q000494:pharmacology; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D003035:Cobalt / Q000378:metabolism / Q000494:pharmacology; D003460:Crystallization; D004247:DNA / Q000378:metabolism; D004563:Electrochemistry; D004722:Endoribonucleases / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology*; D005583:Fourier Analysis; D008274:Magnesium / Q000378:metabolism / Q000494:pharmacology; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009693:Nucleic Acid Hybridization; D011487:Protein Conformation; D012313:RNA / Q000378:metabolism; D016914:Ribonuclease H; D014961:X-Ray Diffraction
D001464:Barium; D003035:Cobalt; D012313:RNA; D004247:DNA; D004722:Endoribonucleases; D016914:Ribonuclease H; D008274:Magnesium; D002118:Calcium