In article <eesnyder.673196910 at beagle>,
eesnyder at boulder.Colorado.EDU (Eric E. Snyder) writes:
|>|>I heard an interesting talk last night... just in passing,
|>the speaker mentioned an invertebrate protein containing
|>17% dihydroxyphenylalanine (aka DOPA)! I couldn't believe
|>|>Have I been living under a rock for the last 25 yrs?
|>I guess so. My early-1970s edition of Lehninger's Biochemistry text discusses
this sort of thing.
|>How common is this protein modification?
|>Exotic amino acids seem to be quite common in structural proteins, such as
chitin in arthropods and collagen and elastin in vertebrates.
|>Is it post-translational?
|>Yes. The amino acid residues are normal phenylalanine after translation.
The modification to DOPA occurs by enzymatic modification of the residues
after the protein is transcribed.
|>Does it occur in vertebrates?
|>I don't know about this particular case, but the general process
(enzymatic formation of exotic amino acids from normal amino acids after
translation) does occur in vertebrates.