obsolete 2,4,4-trimethyl-3-hydroxypentanoyl-CoA dehydrogenase activity (obsolete GO:0034868)
OBSOLETE. Catalysis of the reaction: 2,4,4-trimethyl-3-hydroxypentanoyl-CoA = 2,4,4-trimethyl-3-oxopentanoyl-CoA + 2 H+ + 2 e-.