Editing Hydroxyproline (section)

==Other hydroxyprolines==
Other hydroxyprolines also exist in nature. The most notable ones are 2,3-''cis''-, 3,4-''trans''-, and 3,4-dihydroxyproline, which occurs in [[diatom]] [[cell wall]]s<ref name="Nakajima">{{cite journal | doi = 10.1126/science.164.3886.1400 | last1 = Nakajima | first1 = T. | last2 = Volcani | first2 = B.E. | year = 1969 | title = 3,4-Dihydroxyproline: a new amino acid in diatom cell walls | journal = Science | volume = 164 | issue = 3886| pages = 1400–1401 | pmid = 5783709 | bibcode = 1969Sci...164.1400N | s2cid = 23673503 }}</ref> and are postulated to have a role in [[silica]] deposition.  Hydroxyproline is also found in the walls of [[oomycete]]s, fungus-like protists related to diatoms.<ref name="Alexopoulos 1996">{{Cite book | author = Alexopoulos, C.J., Mims C.W. and Blackwell, M. | year = 1996 | title = Introductory Mycology | edition = 4th | pages = 687–688 | location = New York | publisher = John Wiley & Sons | isbn = 978-0-471-52229-4}}</ref> (2''S'',4''S'')-''cis''-4-Hydroxyproline is found in the toxic [[cyclic peptide]]s from ''[[Amanita]]'' mushrooms (''e.g.'', [[phalloidin]]).<ref>{{cite book | author = Wieland, T. | title = Peptides of Poisonous Amanita Mushrooms | publisher = Springer | year = 1986}}</ref>