Sheng Z, Charbonneau H
Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907-1153.
J Biol Chem. 1993 Mar 5;268(7):4728-33.
The genome of the baculovirus Autographa californica encodes a 19-kDa protein (BVP) containing an active site sequence motif ((I/V)HCXAGXXR(S/T)G) that characterizes a large family of protein tyrosine phosphatases (PTPs). The baculoviral protein was expressed in Escherichia coli and purified so that its enzymatic properties could be examined. We have demonstrated that recombinant BVP has intrinsic protein tyrosine phosphatase activity. Like VH1, a PTP encoded by vaccinia virus, BVP also dephosphorylates seryl or threonyl residues. However, the similarity of BVP to VH1 or the catalytic domains from PTPs of eukaryotic origin is restricted to a small region surrounding the active site motif. In contrast, the similarity of BVP to two putative PTPs encoded by the CDC14 gene of Saccharomyces cerevisiae and a gene of unknown function from Caenorhabditis elegans extends throughout its sequence. We postulate that BVP and its two homologs constitute a unique subfamily that may differ from other PTPs in having a specialized function, mode of regulation, or substrate preference.
苜蓿银纹夜蛾核型多角体病毒的基因组编码一种19 kDa的蛋白质（BVP），该蛋白质含有一个活性位点序列基序（(I/V)HCXAGXXR(S/T)G），这是一大类蛋白质酪氨酸磷酸酶（PTP）的特征。杆状病毒蛋白在大肠杆菌中表达并纯化，以便检测其酶学性质。我们已经证明重组BVP具有内在的蛋白质酪氨酸磷酸酶活性。与痘苗病毒编码的PTP即VH1一样，BVP也能使丝氨酸或苏氨酸残基去磷酸化。然而，BVP与VH1或真核生物来源的PTP催化结构域的相似性仅限于活性位点基序周围的一个小区域。相比之下，BVP与酿酒酵母CDC14基因编码的两个假定PTP以及秀丽隐杆线虫一个功能未知基因的相似性贯穿其整个序列。我们推测BVP及其两个同源物构成一个独特的亚家族，在功能、调控方式或底物偏好方面可能与其他PTP不同。
