张荣娟差异基因.ppt

张荣娟差异基因
JY7（prkA）
文献报道：
丝氨酸蛋白激酶；仅在芽孢杆菌中有报到；是一种cAMP依赖的蛋白激酶作用。
c
b
a
JY6B和JY6（下调）
Disruption of the cgtA gene wion ATPase and release from the membrane
Histidine Residues Are Involved in Translocation-Coupled ATP Hydrolysis by the SecA Protein
Mol Microbiol. 1993 Apr;8(1):31-42.
Characterization of a Bacillus subtilis SecA mutant protein deficient in translocation ATPase and release from the membrane-------It is concluded that the GKT motif in the amino-terminal domain of SecA is part of the catalytic ATP-binding site. This site may be involved in the ATP-driven protein recycling function of SecA which allows the release of SecA from its association with precursor proteins, and the phospholipid bilayer.
secA
SecA protein: autoregulated ATPase catalysing preprotein insertion and translocation across the Escherichia coli inner membran
Recent insight into the biochemical mechanisms of protein translocation in Escherichia coli indicates that SecA ATPase is required both for the initial binding of preproteins to the inner membrane as well as subsequent translocation across this structure. SecA appears to promote these events by direct recognition of the preprotein or preprotein-SecB complex, binding to inner-membrane anionic phospholipids, insertion into the membrane bilayer and association with the preprotein translocator, SecY/SecE. ATP binding appears to control the affinity of SecA for the various components of the system and ATP hydrolysis promotes cycling between its different biochemical states. As a component likely to catalyse a rate-determining step in protein secretion, SecA synthesis is co-ordinated with the activity of the protein export pathway. This form of negative regulation appears to rely on SecA protein binding to its mRNA and repressing translation if conditions of rapid protein secretion prevail within the cell. A precise biochemical scheme for SecA-dependent catalysis of protein export and the details of secA regulation appear to be