1-MethylcarboxylCoA → 1-MethylenecarboxylCoA<br><br>Comments:<br>Carbon chain rearrangement; the 2 carbon can have H, methyl or carboxylate substituents. Based on methylmalonyl-CoA mutase <a href="http://www.chem.qmw.ac.uk/iubmb/enzyme/EC5/4/99/2.html">EC 5.4.99.2</a> and isobutyryl-CoA mutase <a href="http://www.chem.qmw.ac.uk/iubmb/enzyme/EC5/4/99/13.html">EC 5.4.99.13</a> (see <a href="http://www.jbc.org/cgi/content/full/274/44/31679/F1">Figure 1</a> of <a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&list_uids=10531377&dopt=Abstract">Ratnatilleke et al., 1999</a>). CoA ligation to the terminal carboxyl group occurs prior to the reaction but is bypassed in this rule for simplification.
