FH（fumarate hydratase），癌症关联基因，基因ID：2271，该基因编码的蛋白质是三羧酸循环（tca）或krebs循环的酶组分，催化富马酸盐生成L-苹果酸。它以胞质形式和n-末端延伸形式存在，仅在所使用的翻译起始位点不同。n-末端延伸形式的靶向是线粒体，在线粒体中，延伸的移除产生与细胞质中相同的形式。它类似于一些耐高温的Ⅱ类延胡索酸酶，具有四聚体的功能。该基因突变可导致延胡索酸酶缺乏症并导致进行性脑病。[由RefSeq提供，2008年7月]The protein encoded by this gene is an enzymatic component of the tricarboxylic acid (TCA) cycle， or Krebs cycle， and catalyzes the formation of L-malate from fumarate. It exists in both a cytosolic form and an N-terminal extended form， differing only in the translation start site used. The N-terminal extended form is targeted to the mitochondrion， where the removal of the extension generates the same form as in the cytoplasm. It is similar to some thermostable class II fumarases and functions as a homotetramer. Mutations in this gene can cause fumarase deficiency and lead to progressive encephalopathy. [provided by RefSeq， Jul 2008]。