Details zur Publikation

Referenztyp Zeitschriften
DOI / URL Link
Titel (primär) The alkyl tert-butyl ether intermediate 2-hydroxyisobutyrate is degraded via a novel cobalamin-dependent mutase pathway
Autor Rohwerder, T.; Breuer, U.; Benndorf, D.; Lechner, U.; Müller, R.H.;
Journal / Serie Applied and Environmental Microbiology
Erscheinungsjahr 2006
Department UMB; PROTEOM;
Band/Volume 72
Heft 6
Sprache englisch;
Abstract Fuel oxygenates such as methyl and ethyl tert-butyl ether (MTBE and ETBE, respectively) are degraded only by a limited number of bacterial strains. The aerobic pathway is generally thought to run via tert-butyl alcohol (TBA) and 2-hydroxyisobutyrate (2-HIBA), whereas further steps are unclear. We have now demonstrated for the newly isolated ß-proteobacterial strains L108 and L10, as well as for the closely related strain CIP I-2052, that 2-HIBA was degraded by a cobalamin-dependent enzymatic step. In these strains, growth on substrates containing the tert-butyl moiety, such as MTBE, TBA, and 2-HIBA, was strictly dependent on cobalt, which could be replaced by cobalamin. Tandem mass spectrometry identified a 2-HIBA-induced protein with high similarity to a peptide whose gene sequence was found in the finished genome of the MTBE-degrading strain Methylibium petroleiphilum PM1. Alignment analysis identified it as the small subunit of isobutyryl-coenzyme A (CoA) mutase (ICM; EC 5.4.99.13), which is a cobalamin-containing carbon skeleton-rearranging enzyme, originally described only in Streptomyces spp. Sequencing of the genes of both ICM subunits from strain L108 revealed nearly 100% identity with the corresponding peptide sequences from M. petroleiphilum PM1, suggesting a horizontal gene transfer event to have occurred between these strains. Enzyme activity was demonstrated in crude extracts of induced cells of strains L108 and L10, transforming 2-HIBA into 3-hydroxybutyrate in the presence of CoA and ATP. The physiological and evolutionary aspects of this novel pathway involved in MTBE and ETBE metabolism are discussed.
ID 2956
dauerhafte UFZ-Verlinkung https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=2956
Rohwerder, T., Breuer, U., Benndorf, D., Lechner, U., Müller, R.H. (2006):
The alkyl tert-butyl ether intermediate 2-hydroxyisobutyrate is degraded via a novel cobalamin-dependent mutase pathway
Appl. Environ. Microb. 72 (6), 4128 - 4135