Please use this identifier to cite or link to this item: http://nopr.niscair.res.in/handle/123456789/11305
Title: Analysis of Structure of YGNGV Motif Containing Bacteriocins: A Model for Membrane Pore Formation
Authors: Sood, S K
Sinha, P R
Keywords: YGNGV motif
Bacteriocins
Pore formation
Mechanism of action
Structural analysis
LAB
Issue Date: Apr-2003
Publisher: NISCAIR-CSIR, India
Abstract: Bacteriocins from Gram-positive lactic acid bacteria are ribosomally synthesized antimicrobial peptides or proteins, which are known to kill their target by causing dissipation of proton motive force and leakage of small intracellular substances through pore formation in the cell membrane of sensitive bacteria. An YGNGV sequence motif containing bacteriocin comprises an N-terminall)-sheet, a central hinge and a C-terminal amphiphilic either uhelix or I)-sheet. In the proposed model for pore formation, hydrophobic faces of the amphiphilic C-termini interact with each other to form a cylindrical complex. On one end of the cylinder, N-terminal I)-sheets interact with each other through bidentate arms, resulting in a planar ring containing positively charged claws on the bottom face, and this planar ring attaches the bacteriocin complex onto the negative membrane surface. The C-termini then fold back, through a rotation in the hinge region, to reverse polarities and insert themselves in outer lipid monolayer, resulting in a water filled pore that could span only outer monolayer of lipid bilayer, because the length of C-terminus ill, YGNGV containing bacteriocins is just enough to span lipid monolayer. In the subsequent step, some of the half pores translocate across to inner monolayer to form inner half pore. Two half pores in each monolayer may occasionally align to form a conducting channel, thereby causing dissipation of PMF and leakage of small intracellular substances, and death of sensitive bacteria.
Description: 227-235
URI: http://hdl.handle.net/123456789/11305
ISSN: 0975-0967 (Online); 0972-5849 (Print)
Appears in Collections:IJBT Vol.02(2) [April 2003]

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