Catalyzes a carbon-carbon cleavage reaction; cleaves a 2-hydroxy-3-methylacyl-CoA into formyl-CoA and a 2-methyl-branched fatty aldehyde. Peroxisomal 2-OH acyl-CoA lyase involved in the cleavage (C1 removal) reaction in the fatty acid alpha-oxydation in a thiamine pyrophosphate (TPP)-dependent manner. Involved in the degradation of 3-methyl-branched fatty acids like phytanic acid (PubMed:10468558). Involved also in the shortening of 2-hydroxy long-chain fatty acids (By similarity). Plays a significant role in the biosynthesis of heptadecanal in the liver (By similarity). a 2-hydroxy-3-methyl fatty acyl-CoA = a 2-methyl-branched fatty aldehyde + formyl-CoA an (R)-2-hydroxy-long-chain-fatty acyl-CoA = a long-chain fatty aldehyde + formyl-CoA 2-hydroxy-3-methylhexadecanoyl-CoA = 2-methylpentadecanal + formyl-CoA 2-hydroxyoctadecanoyl-CoA = formyl-CoA + heptadecanal 2-hydroxyphytanoyl-CoA = 2,6,10,14-tetramethylpentadecanal + formyl-CoA Binds 1 Mg(2+) ion per subunit. Binds 1 thiamine pyrophosphate per subunit. Optimum pH is 7.5-8. Lipid metabolism; fatty acid metabolism. Homotetramer. Belongs to the TPP enzyme family.