1E68: Solution structure of bacteriocin AS-48

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.
PDB ID: 1E68Download
MMDB ID: 14762
PDB Deposition Date: 2000/8/9
Updated in MMDB: 2000/12
Experimental Method:
solution nmr
Source Organism:
Similar Structures:
Biological Unit for 1E68: monomeric; determined by author
Molecular Components in 1E68
Label Count Molecule
Protein (1 molecule)
As-48 Protein
Molecule annotation
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