Identification and characterization of trimethylamine N-oxide (TMAO) demethylase and TMAO permease in Methylocella silvestris BL2
Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid
Fersiynau electronig
Dangosydd eitem ddigidol (DOI)
Methylocella silvestris, an alphaproteobacterium isolated from a forest soil, can grow on trimethylamine N-oxide (TMAO) as a sole nitrogen source; however, the molecular and biochemical mechanisms underpinning its growth remain unknown. Marker-exchange mutagenesis enabled the identification of several genes involved in TMAO metabolism, including Msil_3606, a permease of the amino acids-polyamine (APC) superfamily, and Msil_3603, consisting of an N-terminal domain of unknown function (DUF1989) and a C-terminal tetrahydrofolate-binding domain. Null mutants of Msil_3603 and Msil_3606 can no longer grow on TMAO. Purified Msil_3603 from recombinant Escherichia coli can convert TMAO to dimethylamine and formaldehyde (1 TMAO → 1 dimethylamine + 1 formaldehyde), confirming that it encodes a bona fide TMAO demethylase (Tdm). Tdm of M. silvestris and eukaryotic Tdms have no sequence homology and contrasting characteristics. Recombinant Tdm of M. silvestris appears to be hexameric, has a high affinity for TMAO (Km = 3.3 mM; Vmax = 21.7 nmol min(-1) mg(-1) ) and only catalyses demethylation of TMAO and a structural homologue, dimethyldodecylamine N-oxide. Our study has contributed to the understanding of the genetic and biochemical mechanisms for TMAO degradation in M. silvestris.
Allweddeiriau
Iaith wreiddiol | Saesneg |
---|---|
Tudalennau (o-i) | 3318-30 |
Nifer y tudalennau | 13 |
Cyfnodolyn | Environmental Microbiology |
Cyfrol | 16 |
Rhif y cyfnodolyn | 10 |
Dyddiad ar-lein cynnar | 3 Awst 2014 |
Dynodwyr Gwrthrych Digidol (DOIs) | |
Statws | Cyhoeddwyd - 1 Hyd 2014 |
Cyhoeddwyd yn allanol | Ie |