Multifunctional enzyme

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Surface / ribbon model of the multifunctional enzyme ATIC (dimer) according to PDB 1PKX. The AICAR formyltransferase domain is yellow and the IMP cyclohydrolase is rendered in blue. Both domains are 50 Å apart and retain their activity when expressed separately. ATIC can be found highly conserved in all living things.

A multifunctional enzyme is a protein that has at least two distinguishable enzymatic activities and two spatially separate centers of activity on one molecule (monomer).

Such an enzyme can arise through translocation . The advantage for the organism is that the efficiency of a metabolic pathway can be increased if two successive reactions take place within the same metabolic pathway on an enzyme and B. the diffusion of substrates is avoided in limited concentration.

The term does not include oligomers of unifunctional enzymes and heterogeneous enzyme complexes . Also included are enzymes such as fatty acid synthase , which have similar activity in several centers, but whose substrates are each different.

The protein database UniProt counted almost 20,000 entries of multifunctional enzymes in all living things in 2010.

See also

Web links

Individual evidence

  1. ↑ Cheong CG, Wolan DW, Greasley SE, Horton PA, Beardsley GP, Wilson IA: Crystal structures of human bifunctional enzyme aminoimidazole-4-carboxamide ribonucleotide transformylase / IMP cyclohydrolase in complex with potent sulfonyl-containing antifolates . In: J. Biol. Chem. . 279, No. 17, April 2004, pp. 18034-45. doi : 10.1074 / jbc.M313691200 . PMID 14966129 .
  2. ↑ Rayl EA, Moroson BA, Beardsley GP: The human pure gene product, 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase / IMP cyclohydrolase. Cloning, sequencing, expression, purification, kinetic analysis, and domain mapping . In: J. Biol. Chem. . 271, No. 4, January 1996, pp. 2225-33. doi : 10.1074 / jbc.271.4.2225 . PMID 8567683 .
  3. ^ H. Robert Horton, Laurence A. Moran, K. Gray Scrimgeour, J. David Rawn, Marc D. Perry: Biochemie . 4th edition. Pearson Studium, 2008, ISBN 3-8273-7312-3 , pp. 211 ff .