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PROSITE documentation PDOC00833

Ribulose-phosphate 3-epimerase family signatures


Ribulose-phosphate 3-epimerase (EC (also known as pentose-5-phosphate 3-epimerase or PPE) is the enzyme that converts D-ribulose 5-phosphate into D-xylulose 5-phosphate in Calvin's reductive pentose phosphate cycle. In Alcaligenes eutrophus two copies of the gene coding for PPE are known [1], one is chromosomally encoded (cbbEC), the other one is on a plasmid (cbbeP). PPE has been found in a wide range of organisms from all kingdoms of life. The sequence of PPE is highly related to:

  • Escherichia coli D-allulose-6-phosphate 3-epimerase (gene alsE).
  • Escherichia coli protein sgcE.

All these proteins have from 209 to 241 amino acid residues.

As signature patterns, we selected two conserved regions which are located in respectively in the N-terminal and in the central part of these proteins.

Last update:

December 2008 / Text revised.

Technical section

PROSITE methods (with tools and information) covered by this documentation:

RIBUL_P_3_EPIMER_1, PS01085; Ribulose-phosphate 3-epimerase family signature 1  (PATTERN)

RIBUL_P_3_EPIMER_2, PS01086; Ribulose-phosphate 3-epimerase family signature 2  (PATTERN)


1AuthorsKusian B., Yoo J.G., Bednarski R., Bowien B.
TitleThe Calvin cycle enzyme pentose-5-phosphate 3-epimerase is encoded within the cfx operons of the chemoautotroph Alcaligenes eutrophus.
SourceJ. Bacteriol. 174:7337-7344(1992).
PubMed ID1429456

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