Dispensable PDZ domain of Escherichia coli YaeL essential protease.
In Escherichia coli, adaptation to extra-cytoplasmic stress relies on sigma(E) activation to induce a rescue pathway. Under non-stressed conditions, sigma(E) is sequestered by the inner membrane protein RseA. Extra-cytoplasmic stress activates DegS-dependent cleavage of RseA, rendering RseA sensitive to further degradation by the YaeL protease. YaeL contains two motifs characteristic of a family of metallo-proteases, as well as a periplasmic PDZ domain. We report results of mutational analyses of the YaeL domains. Surprisingly, expression in a strain depleted for wild-type YaeL or YaeL variants having a 40 amino acid deletion of the PDZ domain or amino acid substitutions of conserved amino acids of the YaeL PDZ domain did not affect cell viability. The proteolytic activity against RseA of these YaeL variants became independent of DegS. These observations suggest that the YaeL PDZ domain exerts a negative control on YaeL activity. Rather than being involved in substrate recognition, the PDZ domain of YaeL is likely to act as an inhibitor of proteolytic activity.
Bohn
Chantal
C
Laboratoire des Réseaux de Régulations et Biogénèse des Enveloppes Bactériennes, Institut de Génétique et Microbiologie, CNRS/UMR 8621, Centre Scientifique d'Orsay, Université Paris-Sud, Bâtiment 400, 91405 Orsay Cedex, France.
Collier
Justine
J
Bouloc
Philippe
P
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D003001:Cloning, Molecular; D004252:DNA Mutational Analysis; D010450:Endopeptidases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009154:Mutation; D010957:Plasmids; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*
D001426:Bacterial Proteins; C066496:DegS protein, Bacteria; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D011994:Recombinant Proteins; C433802:RseA protein, E coli; D014157:Transcription Factors; C489349:degS protein, Escherichia coli; D010450:Endopeptidases; C440001:RseP protein, E coli