期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1991
卷号:88
期号:3
页码:1029-1033
DOI:10.1073/pnas.88.3.1029
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:FK 506, a powerful immunosuppressant that blocks allograft rejection by preventing T-cell activation, binds to an 11-kDa protein called the FK 506-binding protein (FKBP). Like cyclophilin, a cytosolic protein that binds another immunosuppressant, cyclosporin A, FKBP possesses peptidylprolyl cis-trans isomerase activity. We have isolated a genomic clone encoding the yeast FKBP (FKB1). The gene encodes a protein of 114 amino acids having a calculated Mr of 12,158. Disruption of the gene shows that FKB1 is not essential for growth. A search of translated nucleic acid data bases revealed bacterial FKBP homologs in Neisseria meningiditis and Pseudomonas aeruginosa. Comparison of the conserved amino acids in FKBP homologs with the conserved amino acids in the cyclophilins has revealed a region of similarity that we speculate to be a homologous domain related to the functional similarities of the two proteins.