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

FEBS Letters

Morioka, Hiroshi⁴  Hakoshima, Toshio¹  Tomita, Ken-ichi¹  Gohda, Keigo¹  Ikehara, Morio²  Ohtsuka, Eiko⁴  Itoh, Takeshi¹  Nishikawa, Satoshi³  Uesugi, Sei-ichi¹ 

[1] Faculty of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565, Japan;Protein Engineering Research Institute, 6-2-3 Furuedai, Suita, Osaka 565, Japan;Fermentation Research Institute Agency of Industrial Science and Technology, 1-1-3 Higashi, Tsukuba, Ibaragi 305, Japan;Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12jo, Nishi-6chome, Kitaku, Sapporo 060, Hokkaido, Japan

关键词: X-ray;    Recognition;    Non-specific binding;    Mutant RNase T1;    RNase T1;    ribonuclease T1;    K d;    dissociation constant;    F o;    observed structure factor;    F c;    calculated structure factor;    r.m.s. deviation;    root-mean-squares deviation;   

DOI  :  10.1016/0014-5793(91)81263-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Complex of a mutant ribonuclease T₁ (Y4SW) with a non-cognizable ribonucleotide, 2′AMP, has been determined and refined by X-ray diffraction at 1.7 Å 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.

【 授权许可】

Unknown