EC 4.4.1.23     
Accepted name: 2-hydroxypropyl-CoM lyase
Reaction: (1) (R)-2-hydroxypropyl-CoM = (R)-1,2-epoxypropane + HS-CoM
(2) (S)-2-hydroxypropyl-CoM = (S)-1,2-epoxypropane + HS-CoM
Glossary: coenzyme M (CoM) = 2-sulfanylethane-1-sulfonate = 2-mercaptoethanesulfonate (deprecated)
Other name(s): epoxyalkane:coenzyme M transferase; epoxyalkane:CoM transferase; epoxyalkane:2-mercaptoethanesulfonate transferase; coenzyme M-epoxyalkane ligase; epoxyalkyl:CoM transferase; epoxypropane:coenzyme M transferase; epoxypropyl:CoM transferase; EaCoMT; 2-hydroxypropyl-CoM:2-mercaptoethanesulfonate lyase (epoxyalkane-ring-forming); (R)-2-hydroxypropyl-CoM 2-mercaptoethanesulfonate lyase (cyclizing; (R)-1,2-epoxypropane-forming)
Systematic name: (R)-[or (S)-]2-hydroxypropyl-CoM:2-sulfanylethane-1-sulfonate lyase (epoxyalkane-ring-forming)
Comments: Requires zinc. Acts on both enantiomers of chiral epoxyalkanes to form the corresponding (R)- and (S)-2-hydroxyalkyl-CoM adducts. The enzyme will function with some other thiols (e.g., 2-sulfanylethanol) as the nucleophile. Uses short-chain epoxyalkanes from C2 (epoxyethane) to C6 (1,2-epoxyhexane). This enzyme forms component I of a four-component enzyme system click here that is involved in epoxyalkane carboxylation in Xanthobacter sp. strain Py2.
References:
1.  Allen, J.R., Clark, D.D., Krum, J.G. and Ensign, S.A. A role for coenzyme M (2-mercaptoethanesulfonic acid) in a bacterial pathway of aliphatic epoxide carboxylation. Proc. Natl. Acad. Sci. USA 96 (1999) 8432–8437. [PMID: 10411892]
2.  Krum, J.G., Ellsworth, H., Sargeant, R.R., Rich, G. and Ensign, S.A. Kinetic and microcalorimetric analysis of substrate and cofactor interactions in epoxyalkane:CoM transferase, a zinc-dependent epoxidase. Biochemistry 41 (2002) 5005–5014. [PMID: 11939797]
3.  Coleman, N.V. and Spain, J.C. Epoxyalkane: coenzyme M transferase in the ethene and vinyl chloride biodegradation pathways of Mycobacterium strain JS60. J. Bacteriol. 185 (2003) 5536–5545. [PMID: 12949106]
[EC 4.4.1.23 created 2001 as EC 4.2.99.19, transferred 2005 to EC 4.4.1.23]