Function
Oxidizes L-gulono-1,4-lactone to L-xylo-hexulonolactone which spontaneously isomerizes to L-ascorbate. Can use both cytochrome c and phenazine methosulfate as exogenous electron acceptors, but molecular oxygen does not serve as a substrate. Is very specific for the L-gulono-1,4-lactone substrate, since it can not oxidize L-galactono-1,4-lactone, D-glucurono-3,6-lactone, D-glucuronate, D-arabinose, or D-xylose.
Sequence
MSPIWSNWPGEQVCAPSAIVRPTSEAELADVIAQAAKRGERVRAVGSGHSFTDIACTDGVMIDMTGLQRVLDVDQPTGLVTVEGGAKLRALGPQLAQRRLGLENQGDVDPQSITGATATATHGTGVRFQNLSARIVSLRLVTAGGEVLSLSEGDDYLAARVSLGALGVISQVTLQTVPLFTLHRHDQRRSLAQTLERLDEFVDGNDHFEFFVFPYADKALTRTMHRSDEQPKPTPGWQRMVGENFENGGLSLICQTGRRFPSVAPRLNRLMTNMMSSSTVQDRAYKVFATQRKVRFTEMEYAIPRENGREALQRVIDLVRRRSLPIMFPIEVRFSAPDDSFLSTAYGRDTCYIAVHQYAGMEFESYFRAVEEIMDDYAGRPHWGKRHYQTAATLRERYPQWDRFAAVRDRLDPDRVFLNDYTRRVLGP