3 Steps of the regulation of chemotaxis Step 1:response to signal Step 2:controlling flagellar rotation ©Step3:adaptation Chen Feng,Shanghai Jiao Tong University
Chen Feng, Shanghai Jiao Tong University 3 Steps of the regulation of chemotaxis Step 1: response to signal Step 2: controlling flagellar rotation Step 3: adaptation
Bacterial chemotaxis: Attractants sensor kinase Transducer(MCP) CheA Chew ATP CheW CheA CheA- +CH3 Flagellar motor CheR CheB-P CheB CheY CheY-P CheZ response regulators -CH3 CheB and CheY Cytoplasmic membrane Cell wall step1,response to signal趋化过程第一步：对信号作出反应 Chen Feng,Shanghai Jiao Tong University
Chen Feng, Shanghai Jiao Tong University step 1, response to signal 趋化过程第一步: 对信号作出反应 response regulators CheB and CheY sensor kinase CheA Bacterial chemotaxis:
Attractants sensor kinase Transducer(MCP) CheA Chew ATP CheW CheA CheA- +CH3 Flagellar motor CheR CheB-P CheB CheY CheY-P CheZ response regulators -CH3 CheB and CheY Cytoplasmic membrane Cell wall The transducer(MCP)forms a complex with sensor kinase CheA and the coupling protein CheW.This combination results in autophosphorylation of CheA to CheA-P. Attractants decrease the rate of autophosphorylation,whereas repellents increase this rate.MCP与CheA和Chew结合，导致CheA自磷酸化。引诱物降低自磷酸化速率 Chen Feng,Shanghai Jiao Tong University
Chen Feng, Shanghai Jiao Tong University The transducer (MCP) forms a complex with sensor kinase CheA and the coupling protein CheW. This combination results in autophosphorylation of CheA to CheA-P. Attractants decrease the rate of autophosphorylation, whereas repellents increase this rate.MCP与CheA和Chew结合, 导致CheA自磷酸化。引诱物降低自磷酸化速率 response regulators CheB and CheY sensor kinase CheA
Attractants sensor kinase Transducer(MCP) CheA Chew ATP CheW CheA CheA- P +CH3 Flagellar motor CheR CheB-P CheB CheY CheY-P CheZ response regulators -CH3 CheB and CheY Cytoplasmic membrane Cell wall CheA-P can then phosphorylate the response regulators CheB and CheY.Phosphorylated CheY (CheY-P)interacts directly with the flagellar motor switch. Chen Feng,Shanghai Jiao Tong University
Chen Feng, Shanghai Jiao Tong University CheA-P can then phosphorylate the response regulators CheB and CheY. Phosphorylated CheY (CheY-P) interacts directly with the flagellar motor switch. response regulators CheB and CheY sensor kinase CheA
Step 2:Controlling the Rotation of flagellum Attractants Transducer(MCP) ATP CheW CheA CheA +CH3 -Flagellar motor heB CheB CheY CheY-P CheZ CH3 Cytoplasmic membrane Cell wall 国 CheY-P binding to motor switch:clockwise rotation-tumble CheY-P结合于马达开关则鞭毛 顺时针转动（翻滚）： No CheY-P binding:counterclockwise rotation-smooth swimming 无ChY-P时则鞭毛逆时针 转动向前游)： 国 CheZ dephosphorylates CheY-P CheZ对CheY-P脱磷酸化
Step 2: Controlling the Rotation of flagellum CheY-P binding to motor switch: clockwise rotation-tumble CheY-P结合于马达开关则鞭毛 顺时针转动(翻滚); No CheY-P binding: counterclockwise rotation-smooth swimming 无ChY-P时则鞭毛逆时针 转动(向前游); CheZ dephosphorylates CheY-P CheZ对CheY-P脱磷酸化