Regulatory role of C-terminal residues of SulA in its degradation by Lon protease in Escherichia coli.
The SulA protein is a cell division inhibitor in Escherichia coli, and is specifically degraded by Lon protease. To study the recognition site of SulA for Lon, we prepared a mutant SulA protein lacking the C-terminal 8 amino acid residues (SA8). This deletion protein was accumulated and stabilized more than native SulA in lon(+) cells in vivo. Moreover, the deletion SulA fused to maltose binding protein was not degraded by Lon protease, and did not stimulate the ATPase or peptidase activity of Lon in vitro, probably due to the much reduced interaction with Lon. A BIAcore study showed that SA8 directly interacts with Lon. These results suggest that SA8 of SulA was recognized by Lon protease. The SA8 peptide, KIHSNLYH, specifically inhibited the degradation of native SulA by Lon protease in vitro, but not that of casein. A mutant SA8, KAHSNLYH, KIASNLYH, or KIHSNAYH, also inhibited the degradation of SulA, while such peptides as KIHSNLYA did not. These results show that SulA has the specified rows of C-terminal 8 residues recognized by Lon, leading to facilitated binding and subsequent cleavage by Lon protease both in vivo and in vitro.
Ishii
Y
Y
Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Toyama, Shinjuku-ku, Tokyo 162-8640, Japan.
Sonezaki
S
S
Iwasaki
Y
Y
Miyata
Y
Y
Akita
K
K
Kato
Y
Y
Amano
F
F
D018528:ATP-Binding Cassette Transporters; D049069:ATP-Dependent Proteases; D000251:Adenosine Triphosphatases / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002364:Caseins / Q000378:metabolism; D002455:Cell Division; D004926:Escherichia coli / Q000166:cytology / Q000378:metabolism*; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins / Q000378:metabolism*; D058619:Maltose-Binding Proteins; D009004:Monosaccharide Transport Proteins; D009154:Mutation; D049070:Protease La; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017384:Sequence Deletion; D012697:Serine Endopeptidases / Q000378:metabolism*
D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; D002352:Carrier Proteins; D002364:Caseins; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; D058619:Maltose-Binding Proteins; D009004:Monosaccharide Transport Proteins; D011993:Recombinant Fusion Proteins; C461599:maltose transport system, E coli; C053139:sulA protein, E coli; D049069:ATP-Dependent Proteases; D012697:Serine Endopeptidases; C483567:Lon protein, E coli; D049070:Protease La; D000251:Adenosine Triphosphatases