%0 Journal Article %A Adeosun, Ekundayo K. %A Smith, Thomas J. %A Hoberg, Anne-Mette %A Velarde, Giles %A Ford, Robert %A Dalton, Howard %T Formaldehyde dehydrogenase preparations from Methylococcus capsulatus (Bath) comprise methanol dehydrogenase and methylene tetrahydromethanopterin dehydrogenase %D 2004 %J Microbiology, %V 150 %N 3 %P 707-713 %@ 1465-2080 %R https://doi.org/10.1099/mic.0.26707-0 %K FDH, formaldehyde dehydrogenase %K methylene H4MPT-DH, methylene tetrahydromethanopterin dehydrogenase %K ES-MS, electrospray-mass spectrometry %K H4MPT, tetrahydromethanopterin %K MDH, methanol dehydrogenase %K HTSE, heat-treated soluble extract %I Microbiology Society, %X In methylotrophic bacteria, formaldehyde is an important but potentially toxic metabolic intermediate that can be assimilated into biomass or oxidized to yield energy. Previously reported was the purification of an NAD(P)+-dependent formaldehyde dehydrogenase (FDH) from the obligate methane-oxidizing methylotroph Methylococcus capsulatus (Bath), presumably important in formaldehyde oxidation, which required a heat-stable factor (known as the modifin) for FDH activity. Here, the major protein component of this FDH preparation was shown by biophysical techniques to comprise subunits of 64 and 8 kDa in an α 2 β 2 arrangement. N-terminal sequencing of the subunits of FDH, together with enzymological characterization, showed that the α 2 β 2 tetramer was a quinoprotein methanol dehydrogenase of the type found in other methylotrophs. The FDH preparations were shown to contain a highly active NAD(P)+-dependent methylene tetrahydromethanopterin dehydrogenase that was the probable source of the NAD(P)+-dependent formaldehyde oxidation activity. These results support previous findings that methylotrophs possess multiple pathways for formaldehyde dissimilation. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.26707-0