Grenett H E, Ledley F D, Reed L L, Woo S L
Proc Natl Acad Sci U S A. 1987 Aug;84(16):5530-4. doi: 10.1073/pnas.84.16.5530.
A full-length cDNA for tryptophan hydroxylase was cloned from rabbit pineal body by screening an expression library with antibody against rat phenylalanine hydroxylase, which crossreacts with rabbit tryptophan hydroxylase. Clones producing immunoreactive material contain sequences homologous to, yet distinct from, phenylalanine hydroxylase. The rabbit cDNA hybridizes to mRNA in pineal body and brainstem but not in liver. Comparison of the rabbit tryptophan hydroxylase sequence with the sequences of phenylalanine hydroxylase and tyrosine hydroxylase demonstrates that these three biopterin-dependent aromatic amino acid hydroxylases are highly homologous, reflecting a common evolutionary origin from a single primordial genetic locus. The pattern of sequence homology supports the hypothesis that the carboxyl-terminal two-thirds of the molecules constitute the enzymatic activity cores, and the amino-terminal thirds of the molecules constitute domains for substrate specificity.
通过用抗大鼠苯丙氨酸羟化酶的抗体筛选表达文库，从兔松果体中克隆出了色氨酸羟化酶的全长cDNA，该抗体与兔色氨酸羟化酶有交叉反应。产生免疫反应性物质的克隆含有与苯丙氨酸羟化酶同源但又不同的序列。兔cDNA与松果体和脑干中的mRNA杂交，但不与肝脏中的mRNA杂交。将兔色氨酸羟化酶序列与苯丙氨酸羟化酶和酪氨酸羟化酶的序列进行比较表明，这三种依赖生物蝶呤的芳香族氨基酸羟化酶高度同源，反映了它们来自单一原始基因位点的共同进化起源。序列同源性模式支持这样的假说，即分子的羧基末端三分之二构成酶活性核心，而分子的氨基末端三分之一构成底物特异性结构域。
