▁a ▁hom ot et ram er ic ▁li pid - re qu iring ▁en zym e ▁of ▁the ▁mit och ond rial ▁memb rane ▁and ▁has ▁a ▁specific ▁requirement ▁for ▁ph osph at id yl ch oline ▁for ▁optimal ▁en zym atic ▁activity . ▁The ▁encoded ▁protein ▁catal y zes ▁the ▁inter con version ▁of ▁ac eto ac et ate ▁and ▁( R )- 3 - h ydro xy but yr ate , ▁the ▁two ▁major ▁k et one ▁bodies ▁produced ▁during ▁fat ty ▁acid ▁cat abol ism . ▁Alternatively ▁sp lic ed ▁trans cript ▁variants ▁encoding ▁the ▁same ▁protein ▁have ▁been ▁described . ▁ ▁See ▁also ▁▁ 3 - h ydro xy but yr ate ▁de h ydro gen ase ▁ ▁References ▁ ▁External ▁links ▁ ▁Further ▁reading <0x0A> </s> ▁Not ▁to ▁be ▁confused ▁with ▁Fort ▁Clar ence ▁( N ova ▁Scot ia ) ▁ ▁Fort ▁Clar ence ▁is ▁a ▁now ▁def unct ▁fort ification ▁that ▁was ▁located ▁in ▁Ro chester , ▁Kent , ▁England . ▁ ▁History ▁ ▁The ▁fort ▁was ▁built ▁between ▁ 1 8 0 8 ▁and ▁ 1 8 1 2 ▁to ▁prevent ▁inv aders ▁gain ing ▁access ▁from ▁Ma id stone ▁Road ▁to ▁the ▁River ▁Med way . ▁The ▁work ▁was ▁composed ▁of ▁a ▁long ▁brick ▁rev ett ed ▁dry ▁d itch ▁running ▁between ▁a ▁fort ified ▁guard room ▁on ▁the ▁Ro chester - Ma id stone ▁Road ▁to ▁a ▁similar ▁tower ▁alongside ▁the ▁Med way . ▁The ▁principal ▁work ▁( st ill ▁surv iving ) ▁is