Stimulation of the methylcoenzyme M reduction by uridine-5'-diphospho-sugars in cell-free extracts of Methanobacterium thermoautotrophicum (strain delta H).
The hydrogen-dependent reduction of methylcoenzyme M catalyzed by coenzyme-depleted cell-free extracts of Methanobacterium thermoautotrophicum was stimulated by micromolar concentrations of a UDP-disaccharide present in the organism. The compound was isolated and identified as UDP-1-O-alpha-D-2-acetamido-2-deoxyglucopyranose (UDPGlcpNAc) glycosidically linked to 2-acetamido-2-deoxymannopyranosyluronic acid. Maximal stimulation was observed when both the UDP-disaccharide and mercaptoheptanoylthreonine phosphate were present in the reaction mixtures. The UDP derivative isolated was not specific in its action: other UDP-sugars tested in micromolar concentrations stimulated the methylcoenzyme M reduction to the same extent. The activated sugars presumably substitute for ATP, which is usually required in much higher concentrations to activate the methylcoenzyme M reductase system.
Keltjens
J T
JT
Department of Microbiology, University of Nijmegen, The Netherlands.
Kraft
H J
HJ
Damen
W G
WG
van der Drift
C
C
Vogels
G D
GD
D000255:Adenosine Triphosphate / Q000378:metabolism; D002474:Cell-Free System; D002851:Chromatography, High Pressure Liquid; D019605:Euryarchaeota / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008623:Mercaptoethanol; D015080:Mesna / Q000031:analogs & derivatives* / Q000378:metabolism; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism; D013056:Spectrophotometry, Ultraviolet; D014537:Uridine Diphosphate N-Acetylglucosamine / Q000302:isolation & purification*; D014539:Uridine Diphosphate Sugars / Q000302:isolation & purification* / Q000378:metabolism*
D014539:Uridine Diphosphate Sugars; D014537:Uridine Diphosphate N-Acetylglucosamine; C023349:methyl coenzyme M; D008623:Mercaptoethanol; D000255:Adenosine Triphosphate; D010088:Oxidoreductases; C023895:methyl coenzyme M methylreductase; D015080:Mesna