Characterisation of a protease from Escherichia coli involved in hydrogenase maturation.
The large subunits of nickel-containing hydrogenases are synthesised in a precursor form which, after nickel incorporation, is processed by proteolytic cleavage at the C-terminal end. The protease involved in processing of HycE, the large subunit of hydrogenase 3 from Escherichia coli, was purified by three chromatographic steps to apparent homogeneity. Its gene was identified by using a hybridisation probe generated by PCR with oligonucleotide primers the sequence of which was derived from the N-terminal and internal amino acid sequences. Determination of the nucleotide sequence showed that the gene is located distally and as a hitherto uncharacterised gene within the hyc operon, coding for hydrogenase 3 components. It was designated hycI. The HycI protease has a molecular mass of 17 kDa and is a monomer. Its cleavage reaction is not inhibited by conventional inhibitors of serine and metalloproteases, which correlates with the fact that the sequence does not contain signature motifs characteristic of serine-, metallo-, cysteine- or acid proteases. Homologous genes are present in other transcriptional units coding for hydrogenases.
Lehrstuhl für Mikrobiologie, Universität München, Germany.
R
R
Rossmann
T
T
Maier
F
F
Lottspeich
A
A
Böck
D000595:Amino Acid Sequence; D001483:Base Sequence; D004269:DNA, Bacterial; D010450:Endopeptidases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins; D006864:Hydrogenase / Q000378:metabolism*; D008969:Molecular Sequence Data; D011499:Protein Processing, Post-Translational; D017386:Sequence Homology, Amino Acid
D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; C086230:hycE protein, E coli; D006864:Hydrogenase; D010450:Endopeptidases; C100872:HycI protease