Aga1, the first alpha-Galactosidase from the human bacteria Ruminococcus gnavus E1, efficiently transcribed in gut conditions.
Differential gene expression analysis was performed in monoxenic mice colonized with Ruminococcus gnavus strain E1, a major endogenous member of the gut microbiota. RNA arbitrarily primed-PCR fingerprinting assays allowed to specifically detect the in vivo expression of the aga1 gene, which was further confirmed by RT-PCR. The aga1 gene encoded a protein of 744 residues with calculated molecular mass of 85,207 Da. Aga1 exhibited significant similarity with previously characterized α-Galactosidases of the GH 36 family. Purified recombinant protein demonstrated high catalytic activity (104 ± 7 U mg(-1)) and efficient p-nitrophenyl-α-d-galactopyranoside hydrolysis [k(cat)/K(m) = 35.115 ± 8.82 s(-1) mM(-1) at 55 °C and k(cat)/K(m) = 17.48 ± 4.25 s(-1) mM(-1) at 37 °C].
Institut des Sciences Moléculaires de Marseille, ISM2/BiosCiences UMR-CNRS 6263, Service 342, Faculté St Jérôme, Université Paul Cézanne, 13397 Marseille Cedex 20, France. maguiler@ugr.es
Margarita
M
Aguilera
Harivony
H
Rakotoarivonina
Alexandre
A
Brutus
Thierry
T
Giardina
Gwenola
G
Simon
Michel
M
Fons
D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D041981:Gastrointestinal Tract / Q000382:microbiology*; D006801:Humans; D007700:Kinetics; D051379:Mice; D008809:Mice, Inbred C3H; D008969:Molecular Sequence Data; D008970:Molecular Weight; D045857:Ruminococcus / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D000519:alpha-Galactosidase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
D001426:Bacterial Proteins; D000519:alpha-Galactosidase