Myxococcus xanthus spore coat protein S may have a similar structure to vertebrate lens βγ-crystallins
Myxococcus xanthus spore coat protein S may have a similar structure to vertebrate lens βγ-crystallins
复制标题
黄色粘球菌孢子外壳蛋白 S 可能与脊椎动物晶状体 βγ-晶状体蛋白具有相似的结构
作者：
G. Wistow;L. Summers;T. Blundell
The Gram-negative bacterium Myxococcus xanthus has a complex life cycle1 during which large amounts of a protein of relative molecular mass (Mr) 19,000, known as protein S, are assembled into a spore surface coat by a process that specifically requires calcium ions2,3. The gene for protein S has been cloned and the DNA sequence shows that the gene product is composed of four internally repeated homologous sequences, each 40 amino acids long4. Although protein S resembles calmodulin both in its internally duplicated structure and its ability to bind calcium4, it apparently has a β-sheet secondary structure5 rather than the helix–loop–helix motifs that characterize the calmodulin family6–8. We now show that protein S has a striking homology with the β- and γ-crystallins of the vertebrate eye lens9–11 which are β-sheet proteins with internally duplicated structures. This implies that the β- and γ-crystallins evolved from already existing proteins, whose ancestors occurred in the prokaryotes. The biological function of protein S, as a closely packed, stable protein in a relatively dehydrated environment, has implications for the functions of crystalline, which are found closely packed in the lens fibre cells, where their stability is essential for maintenance of transparency.
DOI：
10.1073/pnas.80.22.6829
发表时间：
1983-01-01
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
影响因子：
--
作者：
INOUYE, S;FRANCESCHINI, T;INOUYE, M
通讯作者：
INOUYE, M
完整兔晶状体中钙诱导的高分子量蛋白质。
影响因子：
3.4
作者：
Giblin,FJ;Hightower,KR;Ragatzki,PA;Reddy,VN
通讯作者：
Reddy,VN
DOI：
10.1016/s0021-9258(18)33215-0
发表时间：
1983-01
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
S. Inouye;Y. Ike;Masayori Inouye
通讯作者：
S. Inouye;Y. Ike;Masayori Inouye