A TRYPANOSOMAL CCHC-TYPE ZINC-FINGER PROTEIN WHICH BINDS THE CONSERVED UNIVERSAL SEQUENCE OF KINETOPLAST DNA MINICIRCLES - ISOLATION AND ANALYSIS OF THE COMPLETE CDNA FROM CRITHIDIA-FASCICULATA
A TRYPANOSOMAL CCHC-TYPE ZINC-FINGER PROTEIN WHICH BINDS THE CONSERVED UNIVERSAL SEQUENCE OF KINETOPLAST DNA MINICIRCLES - ISOLATION AND ANALYSIS OF THE COMPLETE CDNA FROM CRITHIDIA-FASCICULATA
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DOI：
10.1128/mcb.13.12.7766
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发表时间：
1993-12-01
影响因子：
5.3
通讯作者：
SHLOMAI, J
中科院分区：
文献类型：
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作者：
ABELIOVICH, H;TZFATI, Y;SHLOMAI, J
动基体DNA小环轻链起始的复制 在一个高度保守的12核苷酸序列，称为通用小环序列。一种束状短翅虫单链DNA结合蛋白与该来源相关序列的富含鸟嘌呤的重链特异性相互作用（Y。Tzfati，H. Abeliovich，1. Kapeller和J. Shlomai，Proc. Natl. Acad. Sci. USA 89：6891-6895，1992）。用通用小环序列重链探针筛选出一株C。从束状锥虫cDNA表达文库中分离出两个编码锥虫通用小环序列结合蛋白的重叠cDNA克隆。完整的cDNA序列定义了一个开放的阅读框架，编码由CCHC锌指基序的五个重复组成的116个氨基酸的多肽链。一个显着的相似性之间发现这个通用的小环序列结合蛋白和其他两个单链DNA结合蛋白在人类和利什曼原虫。所有三种蛋白质都能特异性地与富含鸟嘌呤的单链DNA配体结合。从C. fasciculata的cDNA序列与推测的序列完全一致。在细菌中表达的cDNA编码的融合蛋白的DNA结合特性与内源性C. fasciculata蛋白杂交分析表明，编码小环起源结合蛋白的基因是核基因，可能存在于C。fasciculata染色体作为一个集群的几个结构基因。
Replication of the kinetoplast DNA minicircle light strand initiates at a highly conserved 12-Nucleotide sequence, termed the universal minicircle sequence. A Crithidia fasciculata single-stranded DNA-binding protein interacts specifically with the guanine-rich heavy strand of this origin-associated sequence (Y. Tzfati, H. Abeliovich, 1. Kapeller, and J. Shlomai, Proc. Natl. Acad. Sci. USA 89:6891-6895, 1992). Using the universal minicircle sequence heavy-strand probe to screen a C. fasciculata cDNA expression library, we have isolated two overlapping cDNA clones encoding the trypanosomatid universal minicircle sequence-binding protein. The complete cDNA sequence defines an open reading frame encoding a 116-amino-acid polypeptide chain consisting of five repetitions of a CCHC zinc finger motif. A significant similarity is found between this universal minicircle sequence-binding protein and two other single-stranded DNA-binding proteins identified in humans and in Leishmania major. All three proteins bind specifically to single-stranded guanine-rich DNA ligands. Partial amino acid sequence of the endogenous protein, purified to homogeneity from C. fasciculata, was identical to that deduced from the cDNA nucleotide sequence. DNA-binding characteristics of the cDNA-encoded fusion protein expressed in bacteria were identical to those of the endogenous C. fasciculata protein. Hybridization analyses reveal that the gene encoding the minicircle origin-binding protein is nuclear and may occur in the C. fasciculata chromosome as a cluster of several structural genes.