Structural and Functional Studies of Truncated Hemolysin A from Proteus mirabilis

摘要: In this study we analyzed the structure and function of a truncated form hemolysin A (HpmA265) from Proteus mirabilis using series functional structural studies. Hemolysin belongs to two-partner secretion pathway. The pathway has been identified as most common protein among Gram-negative bacteria. Currently, mechanism action for members is not fully understood. study, hemolysis experiments revealed unidirectional, cooperative, biphasic activity profile after full-length, inactive was seeded with A. We also solved first x-ray TpsA hemolysin. formed right-handed parallel β-helix three adjoining segments anti-parallel β-sheet. CXXC disulfide bond, four buried solvent molecules, carboxyamide ladder were all located at third complete coil. Replacement motif led decreased stability according CD Furthermore, crystal sterically compatible, dry dimeric interface via β-sheet interactions between neighboring monomers. Laser scanning confocal microscopy further supported unidirectional interconversion full-length From these results, model proposed, where β-strand HpmA265 facilitated in part by highly conserved pattern, account template-assisted hemolysis.