Permutation of modules or secondary structure units creates proteins with basal enzymatic properties

FEBS Letters

Kobayashi, Kensei¹  Yanagawa, Hiroshi²  Tsuji, Toru¹ 

[1] Department of Chemistry and Biotechnology, Yokohama National University, Tokiwadai, Hodogaya-ku, Yokohama 240, Japan;Mitsubishi Kasei Institute of Life Sciences, Minamiooya, Machida, Tokyo 194, Japan

关键词: Global sequence space;    Directed evolution;    Combinatorial method;    Induced folding;    Barnase;    Protein evolution;    2′ (3′)-GMP;    guanosine 2′ (3′)-monophosphate;    poly A;    polyadenylic acid;    poly G;    polyguanylic acid;    SDS-PAGE;    sodium dodecyl sulfate-polyacrylamide gel electrophoresis;    CD;    circular dichroism;    eAp;    1-N 6-ethenoadenosine 5′-monophosphate;    Designation of barnase mutants is based on the modules and secondary structure units in them: for example M5324 represents a mutant containing a permutation of the four internal modules in which the six modules of barnase numbered from the N-terminal coding region are rearranged in the order 1;    5;    3;    2;    4;    6. Similarly S4523 represents a mutant containing a permutation of the four internal secondary structure units in which the six structural fragments numbered from the N-terminal coding region are rearranged in the order 1;    4;    5;    2;    3;    6;   

DOI  :  10.1016/S0014-5793(99)00711-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The RNase activity of barnase mutants obtained by the permutation of modules or secondary structure units was investigated. Four of the 45 mutants had weak but distinct RNase activity, and they had unique optimum pHs and temperatures like natural enzymes. One of the active mutants had an ordered conformation, but the others did not. An active mutant having disordered conformation formed an ordered conformation in the presence of GMP, which is an inhibitor of this mutant. These results indicate that the amino acid sequences derived from barnase have sufficient plasticity to be rearranged into different proteins with basal enzymatic properties.

【 授权许可】

Unknown