Reconstitution of signaling in bacterial chemotaxis.

摘要: Strains missing several genes required for chemotaxis toward amino acids, peptides, and certain sugars were tethered their rotational behavior was analyzed. Null strains (called gutted) deleted that code the transducers Tsr, Tar, Tap, Trg cytoplasmic proteins CheA, CheW, CheR, CheB, CheY, CheZ. Motor switch components wild type, flaAII(cheC), or flaBII(cheV). Gutted cells with wild-type motors spun exclusively counterclockwise, while those mutant changed directions of rotation. CheY reduced bias (the fraction time counterclockwise) in either case. CheZ offset effect to an extent varied allele but did not change when tested alone. Transducers also increased presence However, containing failed respond attractants repellents normally detected periplasm. This sensitivity restored by addition CheA CheW. Thus, both enhances clockwise rotation couples flagella. acts, at level motor, as a antagonist. CheW are complete signal pathway. A model is presented explains these results consistent other data found literature.