The ATP-dependent CodWX (HslVU) protease in Bacillus subtilis is an N-terminal serine protease.
HslVU is a two-component ATP-dependent protease, consisting of HslV peptidase and HslU ATPase. CodW and CodX, encoded by the cod operon in Bacillus subtilis, display 52% identity in their amino acid sequences to HslV and HslU in Escherichia coli, respectively. Here we show that CodW and CodX can function together as a new type of two-component ATP-dependent protease. Remarkably, CodW uses its N-terminal serine hydroxyl group as the catalytic nucleophile, unlike HslV and certain beta-type subunits of the proteasomes, which have N-terminal threonine functioning as an active site residue. The ATP-dependent proteolytic activity of CodWX is strongly inhibited by serine protease inhibitors, unlike that of HslVU. Replacement of the N-terminal serine of CodW by alanine or even threonine completely abolishes the enzyme activity. These results indicate that CodWX in B.subtilis represents the first N-terminal serine protease among all known proteolytic enzymes.
Kang
M S
MS
School of Biological Sciences, Seoul National University, Seoul 151-742, Korea.
Lim
B K
BK
Seong
I S
IS
Seol
J H
JH
Tanahashi
N
N
Tanaka
K
K
Chung
C H
CH
D000255:Adenosine Triphosphate / Q000378:metabolism*; D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology*; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D012697:Serine Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology
D017931:DNA Primers; D015842:Serine Proteinase Inhibitors; D000255:Adenosine Triphosphate; C423319:CodWX protease; D012697:Serine Endopeptidases