THE SRCR SUPERFAMILY - A FAMILY REMINISCENT OF THE IG SUPERFAMILY
THE SRCR SUPERFAMILY - A FAMILY REMINISCENT OF THE IG SUPERFAMILY
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DOI：
10.1016/0968-0004(94)90165-1
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发表时间：
1994-01-01
影响因子：
13.8
通讯作者：
KRIEGER, M
中科院分区：
文献类型：
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作者：
RESNICK, D;PEARSON, A;KRIEGER, M
许多蛋白质是由各种各样的保守序列基序组成的分子马赛克，这些基序包含结构上不同的结构域。在许多情况下，这些基序的特征是存在于膜蛋白胞外部分和分泌蛋白中的短的二硫键稳定结构域，2.例如免疫球蛋白重复序列3，4，kringle结构域，表皮生长因子(EGF)4ike重复序列，补体CG/低密度脂蛋白受体结构域，Ly-6重复结构域5，6和P-结构域7。这些结构域非常适合于各种生化任务，包括配体结合，并且很容易与自身或与其他类型的结构域结合来构建复杂的马赛克蛋白。在对I型巨噬细胞清道夫受体1，n的结构分析中发现了一个古老且高度保守的富含半胱氨酸蛋白结构域的家族。这类结构域被命名为SRCR(富含半胱氨酸的清道夫受体)结构域，最初的定义是I型清道夫受体、sDeract受体、CDS/L1和补体因子L(CFI)中每个多肽链存在一个大约101个残基的拷贝1到4个拷贝(总共13个序列，包括9个独立序列和4个来自不同物种的同源物序列)。最近克隆的编码24个额外的独立SRCR结构域和10个额外的同源物的基因，使我们能够修改最初对共识SRCR结构域的描述，并定义两个不同的亚组。使用程序BLASTN和TBLASTN 12鉴定的最近可用的序列是CD6(参考文献)的序列。13)，亲环素C结合蛋白4及其同源物MAC2结合蛋白S(CyCAP/MAC2-BP)，WCL抗原=6，M130(参考文献)。17)，一个新的CR同源物(EMBL登录号：S15468)，以及CD5/LY1(参考文献18，19)和scawenger受体2，21各两个新的同源物。因此，含有SRCR结构域的蛋白家族包括8个不同的成员，分别来自五种哺乳动物(人、牛、鼠、鼠和兔)、一种两栖动物(非洲爪哇)和一种无脊椎动物(海胆)。
Many proteins are molecular mosaics composed of a wide variety of conserved sequence motifs which comprise structurally distinct domains. in many cases, these motifs are characterized by short, disulfide-stabilized domains present in the extracellular portions of membrane proteins and in secreted proteins, 2. Examples include the immunoglobulin repeat 3, 4, kringle domains, epidermal growth factor (EGF) 4ike repeats, complement Cg/LDL-receptor domains, Ly-6 repeats 5, 6 and the P-domain 7. These domains are well suited for a variety of biochemical tasks, including ligand binding, and are readily combined with themselves or with other types of domains for the construction of complex mosaic proteins. Proteins containing as few as one and as many as 36 copies of any one single type of domain have been reported 8, 9. One ancient and highly conserved family of cysteine-rich protein domains was recognized during the analysis of the structure of the type I macrophage scavenger receptor 1, n. This class of domain, designated the SRCR (scavenger receptor cysteine-rich) domain, was initially defined by the presence of one to four copies per polypeptide chain of an approximately 101-residue motif inthe type I scavenger receptor, the sDeract receptor, CDS/Lyl and complement factor l (CFI)(a total of 13 sequences, including nine independent sequences and four sequences of homologs from different species). The recent cloning of genes encoding 24 additional, independent SRCR domains, and ten additional homologs, has allowed us to revise our initial description of the consensus SRCR domain and to define two distinct subgroups. The recently available sequences, which were identified using the programs BLASTN and TBLASTN 12, are those of CD6 (Ref. 13), the cyclophilin-C-binding protein 4 and its homolog the MAC2-binding protein s (CyCAP/MAC2-bp), the WCl antigen= 6, M130 (Ref. 17), a new CR homolog (EMBL accession No. S15468), and two new homologs each of CD5/Lyl (Refs 18, 19) and the scawenger receptor 2, 21. Thus, the superfami~ y of SRCR-domaincontaining proteins, includes eight different members derived from five mammalian (human, bovine, murine, rat and rabbit), one amphibian (Xenopus laevis) and one invertebrate (sea urchin)