title: The bidirectional polar and unidirectional lateral flagellar motors of Vibrio alginolyticus are controlled by a single CheY species.
abstract: The bacterial flagellar motor is an elaborate molecular machine that converts ion-motive force into mechanical force (rotation). One of its remarkable features is its swift switching of the rotational direction or speed upon binding of the response regulator phospho-CheY, which causes the changes in swimming that achieve chemotaxis. Vibrio alginolyticus has dual flagellar systems: the Na(+)-driven polar flagellum (Pof) and the H(+)-driven lateral flagella (Laf), which are used for swimming in liquid and swarming over surfaces respectively. Here we show that both swimming and surface-swarming of V. alginolyticus involve chemotaxis and are regulated by a single CheY species. Some of the substitutions of CheY residues conserved in various bacteria have different effects on the Pof and Laf motors, implying that CheY interacts with the two motors differently. Furthermore, analyses of tethered cells revealed that their switching modes are different: the Laf motor rotates exclusively counterclockwise and is slowed down by CheY, whereas the Pof motor turns both counterclockwise and clockwise, and CheY controls its rotational direction.
authors: Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan.
authors: Masaru
authors: M
authors: Kojima
authors: Rumi
authors: R
authors: Kubo
authors: Toshiharu
authors: T
authors: Yakushi
authors: Michio
authors: M
authors: Homma
authors: Ikuro
authors: I
authors: Kawagishi
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002633:Chemotaxis; D005407:Flagella / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D044149:Vibrio alginolyticus / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins