1E68

Solution structure of bacteriocin AS-48

Summary for 1E68

• Entry DOI: 10.2210/pdb1e68/pdb
• Descriptor: AS-48 PROTEIN (1 entity in total)
• Functional Keywords: antibiotic, bacteriocins, cationic antibacterial peptides, five-helix globule, cyclic polypeptide
• Biological source: ENTEROCOCCUS FAECALIS
• Total number of polymer chains: 1
• Total formula weight: 7177.54

Authors

Gonzalez, C.,Langdon, G.,Bruix, M.,Galvez, A.,Valdivia, E.,Maqueda, M.,Rico, M. (deposition date: 2000-08-09, release date: 2000-10-25, Last modification date: 2024-05-15)

Primary citation

Gonzalez, C.,Langdon, G.,Bruix, M.,Galvez, A.,Valdivia, E.,Maqueda, M.,Rico, M.
Bacteriocin as-48, a Microbial Cyclic Polypeptide Structurally and Functionally Related to Mammalian Nk-Lysin
Proc.Natl.Acad.Sci.USA, 97:11221-, 2000

PubMed Abstract: 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.

PubMed: 11005847
DOI: 10.1073/PNAS.210301097

Experimental method

SOLUTION NMR