HELICASES - AMINO-ACID-SEQUENCE COMPARISONS AND STRUCTURE-FUNCTION-RELATIONSHIPS
HELICASES - AMINO-ACID-SEQUENCE COMPARISONS AND STRUCTURE-FUNCTION-RELATIONSHIPS
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DOI：
10.1016/s0959-440x(05)80116-2
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发表时间：
1993-06-01
影响因子：
6.8
通讯作者：
KOONIN, EV
中科院分区：
文献类型：
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作者：
GORBALENYA, AE;KOONIN, EV
DNA和RNA解旋酶是普遍存在的酶，其介导核酸双链体的核苷三磷酸依赖性解旋，这是基因组复制、表达、重组和修复的必要步骤。所有具有解旋酶活性的蛋白质都含有嘌呤核苷三磷酸结合模式;解旋酶的亚类具有额外的保守基序。解旋酶的三个大的超家族和两个较小的家庭进行了描述。实验结果支持保守模体的解旋酶的结构和功能的预测价值。这些基序中的一些可以在数据库搜索中用作相应解旋酶组的可靠标识符。两个最大的解旋酶超家族共享相似的模式的7个保守的序列基序，其中一些是由长的保守性差的间隔。解旋酶基序似乎被组织在一个核心结构域，提供催化功能，而可选的插入和氨基和羧基末端序列可以包括不同的结构域，具有不同的辅助作用。
DNA and RNA helicases are ubiquitous enzymes that mediate the nucleoside-triphosphate-dependent unwinding of nucleic acid duplexes, a necessary step in genome replication, expression, recombination and repair. All proteins with demonstrated helicase activity contain the purine nucleoside-triphosphate-binding pattern; subsets of helicases possess additional conserved motifs. Three large superfamilies and two smaller families of helicases are described. Experimental results support the value of the conserved motifs for prediction of structure and function of the helicases. Some of these motifs can be used as reliable identifiers of the respective groups of helicases in database searches. The two largest helicase superfamilies share similar patterns of seven conserved sequence motifs, some of which are separated by long poorly conserved spacers. Helicase motifs appear to be organized in a core domain which provides the catalytic function, whereas optional inserts and amino- and carboxy-terminal sequences may comprise distinct domains with diverse accessory roles.