Structural analysis of the murine IgG3 constant region gene.
Structural analysis of the murine IgG3 constant region gene.
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鼠 IgG3 恒定区基因的结构分析。
DOI：
10.1002/j.1460-2075.1984.tb02089.x
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
Blattner,FR
中科院分区：
文献类型：
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作者：
Wels,JA;Word,CJ;Rimm,D;Der-Balan,GP;Martinez,HM;Tucker,PW;Blattner,FR
我们测定了BALB/c小鼠γ 3重链恒定区（C γ 3）基因的完整序列，包括转换位点之前的5′侧翼区和膜外显子末端之后的3′侧翼区。C γ 3编码区是其他IgG的典型编码区，分为6个外显子，分别对应于蛋白质结构域（C γ（3）1、铰链、C γ（3）2和C γ（3）3）和膜羧基末端（M1和M2）。γ 3链的预测氨基酸序列具有三个潜在的N-连接碳水化合物添加位点（包括膜间隔片段中的一个），而其他小鼠IgG中仅出现一个。在转换重组区和C γ 3基因体之间，与C μ和C δ之间的序列存在显著的同源性，这为替代的、T细胞非依赖性类别转换机制提供了理论基础。我们用计算机分析了膜形式的γ 3 mRNA前体的二级结构。我们预测这种RNA前体（约12 000 bp）折叠成四个叶状结构域，分别对应于可变区、大IVS、恒定区主体和膜外显子。这种组织可能在mRNA前体的功能中发挥作用。
We have determined the complete sequence of the gamma 3 heavy chain constant (C gamma 3) region gene of the BALB/c mouse including the 5′‐flanking region up to the switch site and the 3′‐flanking region past the end of the membrane exons. The C gamma 3 coding region, typical of other IgGs, is divided into six exons corresponding to the protein domains (C gamma (3)1, hinge, C gamma (3)2, and C gamma (3)3) and to the membrane carboxyl terminus (M1 and M2). The predicted amino acid sequence of the gamma 3 chain has three potential N‐linked carbohydrate addition sites (including one in the membrane spacer segment), as compared with a single occurrence in the other mouse IgGs. Between the switch recombination region and the body of the C gamma 3 gene, there is a remarkable homology with a sequence between C mu and C delta which provides a rationale for an alternative, T cell‐independent class‐switch mechanism. We have used a computer to analyze the secondary structure of the gamma 3 mRNA precursor for the membrane form. We predict that this RNA precursor (approximately 12 000 bp) folds into four leaf‐like domains which correspond to the variable region, the large IVS, the body of the constant region, and the membrane exons. This organization may have a role to play in the function of the mRNA precursor.