Colle C F, Flowers C C, O'Callaghan D J
Department of Microbiology and Immunology, Louisiana State University Medical Center, Shreveport 71130-3932.
Virology. 1992 Jun;188(2):545-57. doi: 10.1016/0042-6822(92)90509-n.
DNA sequence analysis of the unique short (Us) segment of the genome of equine herpesvirus type 1 Kentucky A strain (EHV-1) by our laboratory and strains Kentucky D and AB1 by other workers identifies a total of nine open reading frames (ORF). In this report, we present the DNA sequence of three of these newly identified ORFs, designated EUS 2, EUS 3, and EUS 4. The EUS 2 ORF is 1146 nucleotides (nt) in length and encodes a potential protein of 382 amino acids. Cis-regulatory sequences upstream of the putative ATG start codon include a G/C box 112 nt upstream and two potential TATA-like elements located between 15 and 90 nt before the ATG. The EUS 2 translation product exhibits significant homology to Ser/Thr protein kinases encoded within the Us segments of other herpesviruses, such as herpes simplex virus (26% homology) and pseudorabies virus (PRV), (45% homology), and possesses sequence domains conserved in protein kinases of cellular and viral origin. The EUS 3 ORF begins 127 nt downstream from the EUS 2 stop codon and ends at a stop codon 1119 nt further downstream. A single TATA-like element maps 61 nt upstream of the ORF. This ORF encodes a potential protein of 373 amino acids and is a homolog of glycoprotein gX of PRV, as judged by overall homology of amino acid residues, cysteine displacement, and presence of potential glycosylation sites and signal sequence. Interestingly, the EUS 4 ORF encodes a potential membrane glycoprotein that does not exhibit homology to any reported protein sequence. The EUS 4 ORF encodes a 383 amino acid polypeptide with a sequence indicative of a signal sequence at its amino terminal end, glycosylation sites for N-linked oligosaccharides, and a transmembrane domain near its carboxyl terminus. Several cis-acting regulatory sequences lie upstream of this ORF. These findings support the observation that the short region of alphaherpesviruses show considerable variation in their genetic content and gene organization.
我们实验室对1型马疱疹病毒肯塔基A株（EHV-1）基因组独特短片段（Us）进行的DNA序列分析，以及其他研究人员对肯塔基D株和AB1株的分析，共鉴定出9个开放阅读框（ORF）。在本报告中，我们展示了其中3个新鉴定的ORF的DNA序列，分别命名为EUS 2、EUS 3和EUS 4。EUS 2开放阅读框长度为1146个核苷酸（nt），编码一个由382个氨基酸组成的潜在蛋白质。推测的ATG起始密码子上游的顺式调控序列包括一个位于上游112 nt处的G/C框，以及两个位于ATG之前15至90 nt之间的潜在TATA样元件。EUS 2翻译产物与其他疱疹病毒Us片段中编码的丝氨酸/苏氨酸蛋白激酶具有显著同源性，如单纯疱疹病毒（同源性26%）和伪狂犬病病毒（PRV，同源性45%），并且具有在细胞和病毒来源的蛋白激酶中保守的序列结构域。EUS 3开放阅读框从EUS 2终止密码子下游127 nt处开始，在再下游1119 nt处的一个终止密码子处结束。一个单一的TATA样元件位于该开放阅读框上游61 nt处。根据氨基酸残基的总体同源性、半胱氨酸置换以及潜在糖基化位点和信号序列的存在判断，该开放阅读框编码一个由373个氨基酸组成的潜在蛋白质，是PRV糖蛋白gX的同源物。有趣的是，EUS 4开放阅读框编码一个潜在的膜糖蛋白，与任何已报道的蛋白质序列均无同源性。EUS 4开放阅读框编码一个由383个氨基酸组成的多肽，其序列在氨基末端有一个指示信号序列的结构，有N-连接寡糖的糖基化位点，在羧基末端附近有一个跨膜结构域。该开放阅读框上游有几个顺式作用调控序列。这些发现支持了α疱疹病毒短区域在遗传内容和基因组织上存在相当大差异的观察结果。
