Bacteriocin AS-48, a microbial cyclic polypeptide structurally and functionally related to mammalian NK-lysin

被引:154
作者
González, C
Langdon, GM
Bruix, M
Gálvez, A
Valdivia, E
Maqueda, M
Rico, M
机构
[1] CSIC, Inst Estructura Mat, E-28006 Madrid, Spain
[2] Univ Jaen, Fac Ciencias Expt, Area Microbiol, Jaen 23071, Spain
[3] Univ Granada, Fac Ciencias, Dept Microbiol, E-18071 Granada, Spain
关键词
cationic antibacterial peptides; NMR solution structure; five-helix globule; cyclic polypeptide; membrane permeation;
D O I
10.1073/pnas.210301097
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
The solution structure of bacteriocin AS-48, a 70-residue cyclic polypeptide from Enterococcus faecalis. consists of a globular arrangement of five alpha-helices enclosing a compact hydrophobic core. The head-to-tail union lies in the middle of helix 5. a fact that is shown to have a pronounced effect on the stability of the three-dimensional structure. Positive charges in the side chains of residues in helix 4 and in the turn linking helix 4 to helix 5 form a cluster that most probably determine its antibacterial activity by promoting pore formation in cell membranes. A similar five-helix structural motif has been found in the antimicrobial NK-lysin. an effector polypeptide of T and natural killer (NK) cells. Bacteriocin AS-48 lacks the three disulfide bridges characteristic of the saposin fold present in NK-lysin, and has no sequence homology with it. Nevertheless, the similar molecular architecture and high positive charge strongly suggest a common mechanism of antibacterial action.
引用
收藏
页码:11221 / 11226
页数:6
相关论文
共 41 条