ZIB

Hits per page

hits 1 - 2 | 2 hits

Sorting

Electronic Resource

Reductive activation of the methyl-tetrahydromethanopterin: coenzyme M methyltransferase from Methanobacterium thermoautotrophicum strain ΔH (1988)

Kengen, Servé W. M. ; Mosterd, Judith J. ; Nelissen, Rob L. H. ; [et al.]

Springer

Archives of microbiology 150 (1988), S. 405-412

add to mindlist on the mindlist

Details

ISSN: 1432-072X

Keywords: Methanobacterium thermoautotrophicum ; Activation ; Corrinoid enzyme ; Methyltransferase ; Methanopterin ; Coenzyme M

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract The enzymatic conversion of formaldehyde to CH3S-CoM in crude extracts of Methanobacterium thermoautotrophicum was used as a means to investigate the methyl-tetrahydromethanopterin: HS-CoM methyltransferase reaction. All components necessary for formaldehyde conversion were shown to be present in a soluble protein fraction. This soluble cell fraction still contained a major amount of corrinoids. Apart from tetrahydromethanopterin no other soluble cofactors were required for formaldehyde conversion. The dependence of the system on catalytic amounts of ATP was shown to be specific. Several nucleoside triphosphates or ADP were unable to substitute for ATP. Remarkably, various strong reducing systems, especially titanium(III)citrate could replace ATP to a large extent. The ATP-dependent formaldehyde conversion to CH3S-CoM was inhibited in the presence of nitrous oxide, detergents or 2′,3′-dialdehyde-ATP. The results support a role for a corrinoid protein in the methyl-tetrahydromethanopterin: HS-CoM methyltransferase reaction at which ATP is involved in the activation of this protein, probably in the conversion of inactive B12a or B12r to active B12s.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00408315

Permalink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

Electronic Resource

Sedimentation during carbonate ramp-to-slope evolution in a tectonically active area: Bowland Basin (Dinantian), northern England (1986)

GAWTHORPE, ROB L.

Oxford, UK : Blackwell Publishing Ltd

Sedimentology 33 (1986), S. 0

add to mindlist on the mindlist

Details

ISSN: 1365-3091

Source: Blackwell Publishing Journal Backfiles 1879-2005

Topics: Geosciences

Notes: The Bowland Basin (northern England) contains a series of carbonates and terrigenous mudstones deposited during the Ivorian to early Brigantian. Two regional depositional environments are indicated by facies and facies associations. Wackestone/packstone and calcarenite facies indicate deposition in a carbonate ramp environment, while lime mudstone/wackestone, calcarenite and limestone breccia/conglomerate facies, often extensively slumped, represent a carbonate slope environment. Stratigraphic relations suggest that the depositional environment evolved from a ramp into a slope through the Dinantian.Two main sediment sources are indicated by the sequence; an extra-basinal terrigenous mud source and a supply of carbonate from the margins of the basin. Deposition from suspension and from sediment gravity flows, in situ production and remobilization of sediment during sedimentary sliding were important processes operating within the basin.Periods of enhanced tectonic activity in the late Chadian to early Arundian and late Asbian to early Brigantian are indicated by basin-wide horizons of sedimentary slide and mass flow deposits. Both intervals were marked by a decline in carbonate production resulting from inundation and uplift/emergence. The first of these intervals separates deposition on a seafloor with gentle topography (carbonate ramp) from a situation where major lateral thickness and facies variations were present and deposition took place in a carbonate slope environment. The second interval marks the end of major carbonate deposition within the Bowland Basin and the onset of regional terrigenous sedimentation.