Aldehyde oxidase carrying an unusual subunit structure from Pseudomonas sp MX-058

Pseudomonas sp. MX-058 produces aldehyde oxidase catalysing glyoxal to glyoxylic acid. Two aldehyde oxidases (F10 and F13) were purified to homogeneity from Pseudomonas sp. MX-058. F10 and F13 had subunit structures, a heterotetramer and heteropentamer respectively. The N-terminal amino acid sequences of all subunits were highly homologous to amino acid sequences of the putative oxidoreductases of Pseudomonas strains. All of these homologous oxidoreductases have a heterotrimer structure consisting of 85-88 (alpha), 37-39 (beta) and 18-23 (gamma) kDa subunits. However, the alpha-subunits of F10 and F13 might have decomposed into two [80 (alpha(1)) and 9 kDa (alpha(2))] and three [58 (alpha(1')), 22 (alpha 1('')) and 9 (alpha(2)) kDa] subunits, respectively, while the beta- and gamma-subunits remained intact. Both F10 and F13 show high activity toward several aliphatic and aromatic aldehydes. The aldehyde oxidases of Pseudomonas sp. MX-058 has unique protein structures, alpha(1)beta(2)beta gamma for F10 and alpha(1')alpha(1 '')alpha(2)beta gamma for F13, a heterotetramer and heteropentamer respectively. The enzymes exhibit significantly low activity toward glyoxylic acid compared with glyoxal, which is an advantageous property for glyoxylic acid production from glyoxal.