5.4.99.64	(R)-3-hydroxybutanoyl-CoA	poor substrate	Aquincola tertiaricarbonis	2-hydroxy-2-methylpropanoyl-CoA	-	r	434952	
5.4.99.64	(R)-3-hydroxybutanoyl-CoA	2-hydroxy-2-methylpropanoyl i.e. 2-hydroxyisobutanoyl-CoA. 2-Hydroxyisobutanoyl-CoA is predominantly converted to (S)-3-hydroxybutanoyl-CoA, and only minor amounts of about 20% of the (R)-enantiomer are obtained	Aquincola tertiaricarbonis	2-hydroxy-2-methylpropanoyl-CoA	-	r	434952	
5.4.99.64	(R)-3-hydroxybutanoyl-CoA	very low activity with wild-type enzyme. Mutations D117V or D117A in the large subunit HcmA result in significantly increased activity toward (R)-3-hydroxybutyryl-CoA	Aquincola tertiaricarbonis	2-hydroxy-2-methylpropanoyl-CoA	-	r	434952	
5.4.99.64	(R)-3-hydroxybutanoyl-CoA	2-hydroxy-2-methylpropanoyl i.e. 2-hydroxyisobutanoyl-CoA. 2-Hydroxyisobutanoyl-CoA is predominantly converted to (S)-3-hydroxybutanoyl-CoA, and only minor amounts of about 20% of the (R)-enantiomer are obtained	Aquincola tertiaricarbonis L108	2-hydroxy-2-methylpropanoyl-CoA	-	r	434952	
5.4.99.64	(R)-3-hydroxybutanoyl-CoA	catalytic efficiency for the (R)-enantiomer is about 11 times higher than for the (S)-enantiomer	Kyrpidia tusciae DSM 2912	2-hydroxybutanoyl-CoA	-	r	436656	
5.4.99.64	(S)-3-hydroxybutanoyl-CoA	-	Aquincola tertiaricarbonis	2-hydroxy-2-methylpropanoyl-CoA	-	r	434960	
5.4.99.64	(S)-3-hydroxybutanoyl-CoA	favorite substrate	Aquincola tertiaricarbonis	2-hydroxy-2-methylpropanoyl-CoA	-	r	434960	
5.4.99.64	(S)-3-hydroxybutanoyl-CoA	-	Aquincola tertiaricarbonis L108	2-hydroxy-2-methylpropanoyl-CoA	-	r	434960	
5.4.99.64	(S)-3-hydroxybutanoyl-CoA	catalytic efficiency for the (R)-enantiomer is about 11 times higher than for the (S)-enantiomer	Kyrpidia tusciae DSM 2912	2-hydroxybutanoyl-CoA	-	r	436672	
5.4.99.64	2,2-dimethylpropanoyl-CoA	wild-type enzyme as well as I90V (HcmA) and I90A (HcmA) mutant enzymes can also isomerize pivaloyl-CoA and isovaleryl-CoA, albeit at more than 10times lower rates than the favorite substrate (S)-3-hydroxybutyryl-CoA	Aquincola tertiaricarbonis	?	-	r	436738	
5.4.99.64	2-hydroxy-2-methylpropanoyl-CoA	-	Aquincola tertiaricarbonis	(S)-3-hydroxybutanoyl-CoA	-	r	434522	
5.4.99.64	2-hydroxy-2-methylpropanoyl-CoA	the enzym plays a central role in the degradation of assorted substrates containing a tert-butyl moiety	Aquincola tertiaricarbonis	(S)-3-hydroxybutanoyl-CoA	-	r	434522	
5.4.99.64	2-hydroxy-2-methylpropanoyl-CoA	2-hydroxy-2-methylpropanoyl i.e. 2-hydroxyisobutanoyl-CoA. 2-Hydroxyisobutanoyl-CoA is predominantly converted to (S)-3-hydroxybutanoyl-CoA, and only minor amounts of about 20% of the (R)-enantiomer are obtained, indicating stereospecific catalysis. The enzyme uses radical chemistry to rearrange the positions of both a methyl group and a hydroxyl group. Compared with Vmax obtained with 2-hydroxyisobutanoyl-CoA, rates with (S)-3-hydroxybutanoyl-CoA are nearly four times higher	Aquincola tertiaricarbonis	(S)-3-hydroxybutanoyl-CoA	-	r	434522	
5.4.99.64	2-hydroxy-2-methylpropanoyl-CoA	the enzym plays a central role in the degradation of assorted substrates containing a tert-butyl moiety	Aquincola tertiaricarbonis L108	(S)-3-hydroxybutanoyl-CoA	-	r	434522	
5.4.99.64	2-hydroxy-2-methylpropanoyl-CoA	2-hydroxy-2-methylpropanoyl i.e. 2-hydroxyisobutanoyl-CoA. 2-Hydroxyisobutanoyl-CoA is predominantly converted to (S)-3-hydroxybutanoyl-CoA, and only minor amounts of about 20% of the (R)-enantiomer are obtained, indicating stereospecific catalysis. The enzyme uses radical chemistry to rearrange the positions of both a methyl group and a hydroxyl group. Compared with Vmax obtained with 2-hydroxyisobutanoyl-CoA, rates with (S)-3-hydroxybutanoyl-CoA are nearly four times higher	Aquincola tertiaricarbonis L108	(S)-3-hydroxybutanoyl-CoA	-	r	434522	
5.4.99.64	2-hydroxyisobutanoyl-CoA	-	Kyrpidia tusciae DSM 2912	(S)-3-hydroxyisobutanoyl-CoA + (R)-3-hydroxyisobutanoyl-CoA	-	r	436778	
5.4.99.64	butanoyl-CoA	low rearrangement activity, corresponding to approximately 2% of the (S)-3-hydroxybutanoyl-CoA conversion rate	Aquincola tertiaricarbonis	isobutanoyl-CoA	-	r	435370	
5.4.99.64	isobutanoyl-CoA	-	Aquincola tertiaricarbonis	butanoyl-CoA	-	r	435533	
5.4.99.64	isobutanoyl-CoA	low rearrangement activity, corresponding to approximately 0.5% of the (S)-3-hydroxybutanoyl-CoA conversion rate	Aquincola tertiaricarbonis	butanoyl-CoA	-	r	435533	
5.4.99.64	isovaleryl-CoA	wild-type enzyme as well as I90V (HcmA) and I90A (HcmA) mutant enzymes can also isomerize pivalyl- and isovaleryl-CoA, albeit at more than 10times lower rates than the favorite substrate (S)-3-hydroxybutyryl-CoA	Aquincola tertiaricarbonis	?	-	?	437627	
5.4.99.64	isovaleryl-CoA	at 10 times lower rate than substrate (S)-3-hydroxybutanoyl-CoA	Aquincola tertiaricarbonis	pentanoyl-CoA	-	r	439631	
5.4.99.64	methylmalonyl-CoA	-	Aquincola tertiaricarbonis	succinyl-CoA	-	r	380077	
5.4.99.64	additional information	the enzyme does not show detectable conversion of methylmalonyl-CoA and succinyl-CoA	Aquincola tertiaricarbonis	?	-	?	89	
5.4.99.64	additional information	(R)-3-hydroxybuytryl-CoA is converted 3.1 times faster than the (S)-enantiomer	Kyrpidia tusciae DSM 2912	?	-	?	89	
5.4.99.64	additional information	the enzyme does not show detectable conversion of methylmalonyl-CoA and succinyl-CoA	Aquincola tertiaricarbonis L108	?	-	?	89	
5.4.99.64	pivaloyl-CoA	at 10 times lower rate than substrate (S)-3-hydroxybutanoyl-CoA	Aquincola tertiaricarbonis	?	-	r	439833