Local variability of the phosphoglycerate kinase-triosephosphate isomerase fusion protein from Thermotoga maritima MSB 8.
The pgk-tpi gene locus of Thermotoga maritima encodes both phosphoglycerate kinase (PGK) and a bienzyme complex consisting of a fusion protein of PGK with triosephosphate isomerase (TIM). No separate tpi gene for TIM is present in T. maritima. A frame-shift at the end of the pgk gene has been previously proposed as a mechanism to regulate the expression of the two protein variants [Schurig et al., EMBO J. 14 (1995), 442-451]. Surprisingly, the complete T. maritima genome was found to contain a pgk-tpi sequence not requiring the proposed frameshift mechanism. To clarify the apparent discrepancy, a variety of DNA sequencing techniques were applied, disclosing an anomalous local variability in the pgk-tpi fusion region. The comparison of different DNA samples and the mass spectrometric analysis of the amino acid sequence of the natural fusion protein from T. maritima MSB8 confirmed the local variability of the DNA variants. Since not all peptide masses could be assigned, further variations are conceivable, suggesting an even higher heterogeneity of the T. maritima MSB8 strain.
Wassenberg
D
D
Institut für Biophysik und Physikalische Biochemie, Universität Regensburg, Germany.
Wuhrer
M
M
Beaucamp
N
N
Schurig
H
H
Wozny
M
M
Reusch
D
D
Fabry
S
S
Jaenicke
R
R
D000595:Amino Acid Sequence / Q000235:genetics; D001426:Bacterial Proteins; D001483:Base Sequence / Q000235:genetics; D016368:Frameshift Mutation / Q000235:genetics*; D014644:Genetic Variation / Q000235:genetics*; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000235:genetics*; D010735:Phosphoglycerate Kinase / Q000235:genetics*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D020124:Thermotoga maritima / Q000235:genetics*; D014305:Triose-Phosphate Isomerase / Q000235:genetics*
D001426:Bacterial Proteins; D009097:Multienzyme Complexes; C109485:PGK-TIM fusion protein, Thermotoga maritima; D010735:Phosphoglycerate Kinase; D014305:Triose-Phosphate Isomerase