Vit C

Jerry Learn learn at
Tue Jan 30 14:37:00 EST 1996

In article <4eii8q$9fg at>, robison at
(Keith Robison) wrote:

>IAN DWORKIN (idworkin at wrote:
>: In article <31004A7C.6EDC1F90 at>, Chris Barry
<chbarry at> writes:
>: >I read on one of the newsgroups recently that man is one of the few
>: >mamals that don't produce vitamine C. There were a couple of follow up
>: >articles to the thread that seemed to confirm the statement. The
>: >statement has been bothering me since. I seem to recall that some people
>: >can produce vitamine C. Am I wrong? Are you aware of an article that can
>: >confirm/refute their statement? Thanks in advance.
>: >
>: >Chris
>:  As far as I know, no human is capable of producing ascorbic acid, the enzyme
>: which we are missing for the completion of the biosynthetic [pathway is
>: in the human genome as a pseudogene. Since it intiailly lost its function, it
>: has become a neutral marker, and thus has been subject to alot of nucleotide
>: substitutions. If i remember correctly there are a few exons which are
>: reasonably intact, but I would have to look it up. If you are very
>Could you post the name of the enzyme?  This sort of question
>comes up periodically.

I'm not an expert but here is some the header for the GenBank entry that I
dug up from a Medline search:

LOCUS       HUMGULOB     3364 bp    DNA             PRI       15-SEP-1995
DEFINITION  Human GULO gene for L-gulono-gamma-lactone oxidase, exon 9,10 and
KEYWORDS    L-gulono-gamma-lactone oxidase; biosynthesis of L-ascorbic acid;
            flavin enzyme.
SOURCE      Homo sapiens peripheral blood (library: lambda phage, EMBL4) DNA,
            clone lambda HGO8.
  ORGANISM  Homo sapiens
            Eukaryotae; mitochondrial eukaryotes; Metazoa; Chordata;
            Vertebrata; Sarcopterygii; Mammalia; Eutheria; Primates;
            Catarrhini; Hominidae; Homo.
REFERENCE   1  (bases 1 to 3364)
  AUTHORS   Nishikimi,M., Fukuyama,R., Minoshima,S., Shimizu,N. and Yagi,K.
  TITLE     Cloning and chromosomal mapping of the human nonfunctional gene for
            L-gulono-gamma-lactone oxidase, the enzyme for L-ascorbic acid
            biosynthesis missing in man
  JOURNAL   J. Biol. Chem. 269 (18), 13685-13688 (1994)
  MEDLINE   94230484
Jerry Learn

Research Associate

Dept. of Microbiology             | Learn at
University of Washington          | Phone: (206) 616-4286
Box 357740                        |   FAX: (206) 616-1575
Seattle, WA  98195-7740  USA      |     or (206) 543-8297 

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