Non-cognizable ribonucleotide, 2'AMP, binds to a mutant ribonuclease T1 (Y45W) at a new base-binding site but not at the guanine-recognition site.
Complex of a mutant ribonuclease T1 (Y45W) with a non-cognizable ribonucleotide, 2'AMP, has been determined and refined by X-ray diffraction at 1.7 A resolution. The 2'AMP molecule locates at a new base-binding site which is remote from the guanine-recognition site, where 2'GMP was found to be bound. The nucleotide adopts the anti conformation of the glycosidic bond and C3'-exo sugar pucker. There exists a single hydrogen bond between the adenine base and the enzyme, and, therefore, the site found is apparently a non-specific binding site. The results indicate that the binding of 2'AMP to the guanine-recognition site is weaker than that to the new binding site.
Hakoshima
T
T
Faculty of Pharmaceutical Sciences, Osaka University, Japan.
Itoh
T
T
Gohda
K
K
Tomita
K
K
Uesugi
S
S
Nishikawa
S
S
Morioka
H
H
Ohtsuka
E
E
Ikehara
M
M
D000249:Adenosine Monophosphate / Q000378:metabolism*; D000595:Amino Acid Sequence; D001236:Aspergillus oryzae / Q000201:enzymology; D001665:Binding Sites; D003461:Crystallography; D006157:Guanosine Monophosphate / Q000378:metabolism; D006860:Hydrogen Bonding; D007536:Isomerism; D008958:Models, Molecular; D015394:Molecular Structure; D009154:Mutation; D011994:Recombinant Proteins / Q000648:ultrastructure; D006163:Ribonuclease T1 / Q000378:metabolism* / Q000648:ultrastructure; D013329:Structure-Activity Relationship; D014961:X-Ray Diffraction
D011994:Recombinant Proteins; C026693:2'-guanylic acid; D000249:Adenosine Monophosphate; D006157:Guanosine Monophosphate; D006163:Ribonuclease T1