Tiedeman A A, Smith J M, Zalkin H
J Biol Chem. 1985 Jul 25;260(15):8676-9.
GMP synthetase (EC 6.3.4.1), a glutamine amido-transferase encoded by the guaA gene, catalyzes the synthesis of GMP from XMP. The guaA gene was subcloned from the Clarke and Carbon (Clarke, L., and Carbon, J. (1976) Cell 9, 91-99) plasmid pLC34-10, and the nucleotide sequence was determined. The structural gene encodes a protein of 525 amino acid residues having a calculated Mr of 58,604. The amino acid sequence of the NH2 terminus of GMP synthetase was determined and used to verify the translation start site determined from the DNA sequence. A 68-base pair intercistronic region separates guaA from the upstream guaB gene in the polycistronic guaBA operon. The 3' end of the guaA mRNA was determined by S1 nuclease mapping. The 3' end of guaA mRNA is 36-37 nucleotides downstream of the translation stop codon within a region of dyad symmetry that resembles a rho-independent transcription termination site.
GMP合成酶（EC 6.3.4.1）是一种由guaA基因编码的谷氨酰胺酰胺转移酶，催化从XMP合成GMP。guaA基因是从克拉克和卡尔文（克拉克，L.，和卡尔文，J.（1976年）《细胞》9，91 - 99）的质粒pLC34 - 10中亚克隆出来的，并测定了其核苷酸序列。该结构基因编码一个由525个氨基酸残基组成的蛋白质，计算所得的分子量为58,604。测定了GMP合成酶NH2末端的氨基酸序列，并用于验证从DNA序列确定的翻译起始位点。在多顺反子guaBA操纵子中，一个68个碱基对的顺反子间区域将guaA与上游的guaB基因分隔开。通过S1核酸酶作图确定了guaA mRNA的3'末端。guaA mRNA的3'末端在翻译终止密码子下游36 - 37个核苷酸处，位于一个具有二元对称的区域内，该区域类似于一个不依赖于rho的转录终止位点。
