O'Neill R R, Tokoro T, Kozak C A, Brady R O
Developmental and Metabolic Neurology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892.
Proc Natl Acad Sci U S A. 1989 Jul;86(13):5049-53. doi: 10.1073/pnas.86.13.5049.
To study structure-function relationships and molecular evolution, we determined the nucleotide sequence and chromosomal location of the gene encoding murine glucocerebrosidase (glucosylceramidase; D-glucosyl-N-acylsphingosine glucohydrolase, EC 3.2.1.45). In the protein coding region of the murine cDNA, the nucleotide sequence and the corresponding deduced amino acid sequences were 82% and 86% identical to the respective human sequences. All five amino acids presently known to be essential for normal enzymatic activity were conserved between mouse and man. The murine enzyme had a single deletion relative to the human enzyme at amino acid number 273. One ATG translation initiation signal was present in the mouse sequence in contrast to the human sequence, where two start codons have been reported. Nucleotide sequencing of a clone derived from murine genomic DNA revealed that the murine signal for translation initiation was located in exon 2. The locations of all 10 introns were conserved among mouse and man. We mapped the genetic locus for glucocerebrosidase to mouse chromosome 3, at a position 7.6 +/- 3.2 centimorgans from the locus for the beta subunit of nerve growth factor. Comparison of linkage relationships in the human and murine genome indicates that these closely linked mouse genes are also syntenic on human chromosome 1 but in positions that span the centromere.
为了研究结构-功能关系和分子进化,我们确定了编码小鼠葡糖脑苷脂酶(葡萄糖基神经酰胺酶;D-葡萄糖基-N-酰基鞘氨醇葡萄糖水解酶,EC 3.2.1.45)的基因的核苷酸序列和染色体定位。在小鼠cDNA的蛋白质编码区,核苷酸序列和相应推导的氨基酸序列与各自的人类序列分别有82%和86%的同一性。目前已知对正常酶活性至关重要的所有五个氨基酸在小鼠和人类之间是保守的。相对于人类酶,小鼠酶在第273位氨基酸处有一个单一缺失。与人类序列不同,小鼠序列中有一个ATG翻译起始信号,而人类序列中已报道有两个起始密码子。对源自小鼠基因组DNA的一个克隆进行核苷酸测序表明,小鼠的翻译起始信号位于外显子2中。小鼠和人类之间所有10个内含子的位置都是保守的。我们将葡糖脑苷脂酶的基因座定位到小鼠的3号染色体上,距神经生长因子β亚基的基因座7.6±3.2厘摩。人类和小鼠基因组中连锁关系的比较表明,这些紧密连锁的小鼠基因在人类1号染色体上也是同线的,但跨越了着丝粒的位置。