The role of the Corynebacterium glutamicum rel gene in (p)ppGpp metabolism.
To investigate the metabolism of (p)ppGpp in amino-acid-producing coryneform bacteria, a PCR-based strategy using degenerate consensus oligonucleotides was applied to isolate the rel gene of Corynebacterium glutamicum ATCC 13032. The gene consists of 2283 nucleotides and encodes a protein of 760 amino acids with a molecular mass of 84.4 kDa. The amino acid sequence revealed extensive similarities to the related proteins RelA and SpoT of Escherichia coli, which are known to be involved in (p)ppGpp biosynthesis and degradation. The C. glutamicum rel gene is located downstream of the apt gene encoding an adenine phosphoribosyltransferase, and an ORF with similarities to dciAE, which represents part of a dipeptide transport system in E. coli. A C. glutamicum mutant strain carrying a defined deletion in the rel gene was constructed. This mutant failed to accumulate (p)ppGpp in response to amino acid starvation. When overexpressed in E. coli, the C. glutamicum rel gene was able to reverse growth defects caused by an overexpressed relA gene. It is proposed that the C. glutamicum rel gene encodes a bifunctional enzyme with (p)ppGpp synthetase and (p)ppGpp-degrading activities.
Lehrstuhl fr Genetik, Fakultut fr Biologie, Universitt BielefeldD-33501 BielefeldGermany.
Lutz
L
Wehmeier
Lehrstuhl fr Genetik, Fakultut fr Biologie, Universitt BielefeldD-33501 BielefeldGermany.
Andreas
A
Schafer
Institut fr Biochemie 1, Universitt zu KlnD-50674 KlnGermany.
Andreas
A
Burkovski
Institut fr Biochemie 1, Universitt zu KlnD-50674 KlnGermany.
Reinhard
R
Krmer
Institut fr Molekularbiologie, Universitt JenaD-07745 JenaGermany.
Undine
U
Mechold
Institut fr Molekularbiologie, Universitt JenaD-07745 JenaGermany.
Horst
H
Malke
Lehrstuhl fr Genetik, Fakultut fr Biologie, Universitt BielefeldD-33501 BielefeldGermany.
Alfred
A
Phler
Lehrstuhl fr Genetik, Fakultut fr Biologie, Universitt BielefeldD-33501 BielefeldGermany.
Jrn
J
Kalinowski
D000228:Adenine Phosphoribosyltransferase / Q000378:metabolism; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000378:metabolism; D015139:Blotting, Southern; D003001:Cloning, Molecular; D003352:Corynebacterium / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli; D005798:Genes, Bacterial / Q000235:genetics / Q000502:physiology*; D008025:Ligases / Q000235:genetics* / Q000502:physiology; D008969:Molecular Sequence Data; D009857:Oncogenes / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011755:Pyrophosphatases / Q000235:genetics* / Q000502:physiology; D017386:Sequence Homology, Amino Acid
D000596:Amino Acids; D000228:Adenine Phosphoribosyltransferase; C027627:guanosine-3',5'-bis(diphosphate) 3'-pyrophosphatase; D011755:Pyrophosphatases; D008025:Ligases; C028812:guanosine 3',5'-polyphosphate synthetases