Lu Y, O'Dowd B F, Orrego H, Israel Y
Department of Pharmacology, University of Toronto, Ontario, Canada.
Biochem Biophys Res Commun. 1992 Dec 15;189(2):749-58. doi: 10.1016/0006-291x(92)92265-y.
We have cloned and sequenced a full-length cDNA (1083 bp) encoding the human liver cystathionine-gamma-lyase enzyme (cystathionase). The human cystathionase sequence presented a substantial deletion of 132 bases (44 amino acids) compared to that reported for rat cystathionase, and of 135 bases (45 amino acids) compared to that reported for yeast cystathionase. After re-alignment for the missing nucleotides, the human cDNA sequence shows significant amino acid homology to that for the rat enzyme (85%) and the yeast enzyme (50%). A search for an undeleted cDNA, by the polymerase chain reaction, yielded a second clone which contained the missing 132 bases. Flanking nucleotides in the latter clone were identical to those in the cDNA clone containing the deletion. The two forms of human cystathionase deduced from the two cDNA clones may be derived from two different genes or may be splice variants.
我们已克隆并测序了编码人肝脏胱硫醚-γ-裂解酶（胱硫醚酶）的全长cDNA（1083 bp）。与报道的大鼠胱硫醚酶序列相比，人胱硫醚酶序列有132个碱基（44个氨基酸）的大量缺失，与报道的酵母胱硫醚酶序列相比有135个碱基（45个氨基酸）的缺失。对缺失核苷酸重新比对后，人cDNA序列与大鼠酶（85%）和酵母酶（50%）的氨基酸序列具有显著同源性。通过聚合酶链反应寻找未缺失的cDNA，得到了第二个克隆，其包含缺失的132个碱基。后一个克隆中的侧翼核苷酸与含有缺失的cDNA克隆中的相同。从两个cDNA克隆推导的两种形式的人胱硫醚酶可能来自两个不同的基因，也可能是剪接变体。
