Papers - YOKOTA Kenji
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Crystal Structure of Staphylococcal LukF Delineates Conformational Changes Accompanying Formation of a Transmembrane Channel Reviewed International coauthorship
Rich Olson, Hirofumi Nariya, Kenji Yokota, Yoshiyuki Kamio, Eric Gouaux
Nature Structural Biology IF:13.563 6 ( 2 ) 134 - 140 1999.02
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
Staphylococcal LukF, LukS, HgammaII, and alpha-hemolysin are self-assembling, channel-forming proteins related in sequence and function. In the alpha-hemolysin heptamer, the channel-forming beta-strands and the amino latch make long excursions from the protomer core. Here we report the crystal structure of the water soluble form of LukF. In the LukF structure the channel-forming region folds into an amphipathic, three-strand beta-sheet and the amino latch forms a beta-strand extending a central beta-sheet. The LukF structure illustrates how a channel-forming toxin masks protein-protein and protein-membrane interfaces prior to cell binding and assembly, and together with the alpha-hemolysin heptamer structure, they define the end points on the pathway of toxin assembly.
DOI： https://doi.org/10.1038/5821
Other Link： http://www.nature.com/nsmb/journal/v6/n2/full/nsb0299_134.html
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Further Study on the Two Pivotal Parts of Hlg2 for the Full Hemolytic Activity of Staphylococcal gamma-Hemolysin Reviewed
Kenji Yokota, Noriko Sugawara, Hirofumi Nariya, Jun Kaneko, Toshio Tomita, Yoshiyuki Kamio
Bioscience, Biotechnology, and Biochemistry 62 ( 9 ) 1745 - 1750 1998.09
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
Staphylococcal gamma-hemolysin consists of LukF of 34 kDa and Hlg2 (or H gamma II) of 32 kDa, which cooperatively lyse human and rabbit erythrocytes. Our previous data showed that the 5-residue segment K23R24L25A26I27 of Hlg2 is pivotal for the hemolytic activity [Nariya, H. and Kamio, Y., Biosci. Biotechnol. Biochem., 59, 1603-1604 (1997)]. Here, we identify an additional amino acid residue in Hlg2 necessary for the full gamma-hemolysin activity by measuring the toxin activity of Hlg2 mutants in the presence of LukF. The data obtained showed that Arg217 of Hlg2 is an additional pivotal amino acid residue besides the KRLAI segment for the full Hlg2-specific function in gamma-hemolysin. We also report evidence that the Hlg2 mutants showing a low or null hemolytic activity in the presence of LukF towards human erythrocytes had low or no binding activity to the cells, resulting in failure of formation of the ring-shaped pore-forming complex on the erythrocytes.
DOI： https://doi.org/10.1271/bbb.62.1745
Other Link： https://www.jstage.jst.go.jp/article/bbb/62/9/62_9_1745/_pdf