Global InformationMuconate lactonizing enzyme information
| Muconate cycloisomerase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 Muconate cycloisomerase oktamer, Thermotoga maritima | |||||||||
| Identifiers | |||||||||
| EC no. | 5.5.1.1 | ||||||||
| CAS no. | 9023-72-7 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| |||||||||
Muconate lactonizing enzymes (EC 5.5.1.1, muconate cycloisomerase I, cis,cis-muconate-lactonizing enzyme, cis,cis-muconate cycloisomerase, 4-carboxymethyl-4-hydroxyisocrotonolactone lyase (decyclizing), CatB, MCI, MLE, 2,5-dihydro-5-oxofuran-2-acetate lyase (decyclizing)) are involved in the breakdown of lignin-derived aromatics, catechol and protocatechuate, to citric acid cycle intermediates as a part of the β-ketoadipate pathway in soil microbes. Some bacterial species are also capable of dehalogenating chloroaromatic compounds by the action of chloromuconate lactonizing enzymes. MLEs consist of several strands which have variable reaction favorable parts therefore the configuration of the strands affect its ability to accept protons.[1] The bacterial MLEs belong to the enolase superfamily, several structures from which are known.[2][3][4] MLEs have an identifying structure made up of two proteins and two Magnesium ions as well as various classes depending on whether it is bacterial or eukaryotic.[5][6] The reaction mechanism that MLEs undergo are the reverse of beta-elimination in which the enolate alpha-carbon is protonated.[7] MLEs can undergo mutations caused by a deletion of catB structural genes which can cause some bacteria to lose its functions such as the ability to grow.[8] Additional mutations to MLEs can cause its structure and function to alter and could cause the conformation to change therefore making it an inactive enzyme that is unable to bind its substrate.[1] There is another enzyme called Mandelate Racemase that is very similar to MLEs in the structural way as well as them both being a part of the enolase superfamily. They both have the same end product even though they undergo different chemical reactions in order to reach the end product.[9][10]
- ^ a b Kajander T, Lehtiö L, Schlömann M, Goldman A (September 2003). "The structure of Pseudomonas P51 Cl-muconate lactonizing enzyme: co-evolution of structure and dynamics with the dehalogenation function". Protein Science. 12 (9): 1855–64. doi:10.1110/ps.0388503. PMC 2323983. PMID 12930985.
- ^ Ornston LN (August 1966). "The conversion of catechol and protocatechuate to beta-ketoadipate by Pseudomonas putida. 3. Enzymes of the catechol pathway". The Journal of Biological Chemistry. 241 (16): 3795–9. doi:10.1016/S0021-9258(18)99841-8. PMID 5330966.
- ^ Ornston, L.N. (1970). "Conversion of catechol and protocatechuate to β-ketoadipate (Pseudomonas putida)". Metabolism of Amino Acids and Amines Part A. Methods in Enzymology. Vol. 17A. pp. 529–549. doi:10.1016/0076-6879(71)17237-0. ISBN 9780121818746.
- ^ Sistrom WR, Stanier RY (October 1954). "The mechanism of formation of beta-ketoadipic acid by bacteria". The Journal of Biological Chemistry. 210 (2): 821–36. doi:10.1016/S0021-9258(18)65409-2. PMID 13211620.
- ^ NCBI/CBB/Structure group. "3DG3: Crystal Structure Of Muconate Lactonizing Enzyme From Mucobacterium Smegmatis". www.ncbi.nlm.nih.gov. Retrieved 2018-11-27.
- ^ Kajander, Tommi; Merckel, Michael C.; Thompson, Andrew; Deacon, Ashley M.; Mazur, Paul; Kozarich, John W.; Goldman, Adrian (2002-04-01). "The Structure of Neurospora crassa 3-Carboxy-cis,cis-Muconate Lactonizing Enzyme, a β Propeller Cycloisomerase". Structure. 10 (4): 483–492. doi:10.1016/S0969-2126(02)00744-X. ISSN 0969-2126. PMID 11937053.
- ^ Tommi K (2003). Structural evolution of function and stability in muconate lactonizing enzymes. University of Helsinki. ISBN 978-9521003387. OCLC 58354177.
- ^ Wheelis ML, Ornston LN. Genetic Control of Enzyme Induction in the β-Ketoadipate Pathway of Pseudomonas putida: Deletion Mapping of cat Mutations. OCLC 678549695.
- ^ Neidhart DJ, Kenyon GL, Gerlt JA, Petsko GA (October 1990). "Mandelate racemase and muconate lactonizing enzyme are mechanistically distinct and structurally homologous". Nature. 347 (6294): 692–4. Bibcode:1990Natur.347..692N. doi:10.1038/347692a0. PMID 2215699. S2CID 4350795.
- ^ Frey PA, Northrop DB (1999). Enzymatic mechanisms. Amsterdam: IOS Press. ISBN 978-9051994322. OCLC 40851146.