GVPCS WITH REDUCED NUMBERS OF REPEATING SEQUENCE ELEMENTS BIND TO AND STRENGTHEN CYANOBACTERIAL GAS VESICLES
GVPCS WITH REDUCED NUMBERS OF REPEATING SEQUENCE ELEMENTS BIND TO AND STRENGTHEN CYANOBACTERIAL GAS VESICLES
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DOI：
10.1111/j.1365-2958.1995.mmi_17010147.x
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发表时间：
1995-07-01
影响因子：
3.6
通讯作者：
HAYES, PK
中科院分区：
文献类型：
--
作者：
KINSMAN, R;WALSBY, AE;HAYES, PK
我们先前已经证明，气泡蛋白GvpC存在于气泡的外表面，可以被可逆地去除并反弹到表面，并增加气泡的临界崩溃压力。GvpC分子含有5个部分保守的重复序列，33个氨基酸(33-RR)夹在18个N-端和10个C-端氨基酸之间，与形成气泡肋骨的GvpA分子的比例为1：25。通过使用重组技术，我们现在已经制造出只包含33个氨基酸重复序列中的前两个、三个或四个重复序列的GvpC的修改版本。所有这些蛋白质都结合并加强了被剥夺了天然GvpC的气泡。含有三个或四个重复的重组蛋白的结合量与天然蛋白质的33-RR：GvpA的比率(即1：5)相同，并且它们恢复了气泡的大部分强度；然而，只包含两个重复的蛋白质以较低的比率(1：7.7)结合，并且恢复的强度较少。只有两个、三个或四个33个氨基酸重复的祖先蛋白质本可以增强气泡的功能，但重复次数的逐渐增加将提供强度和效率的提高。
We have previously shown that the gas-vesicle protein GvpC is present on the outer surface of the gas vesicle, can be reversibly removed and rebound to the surface, and increases the critical collapse pressure of the gas vesicle. The GvpC molecule, which contains five partially conserved repeats of 33 amino acids (33-RR) sandwiched between 18 N-terminal and 10 C-terminal amino acids, is present in a ratio of 1:25 with the GvpA molecule, which forms the ribs of the gas vesicle. By using recombinant techniques we have now made modified versions of GvpC that contain only the first two, three or four of the 33-amino-acid repeats. All of these proteins bind to and strengthen gas vesicles that have been stripped of their native GvpC. Recombinant proteins containing three or four repeats bind in amounts that give the same ratio of 33-RR:GvpA (i.e. 1:5) as the native protein, and they restore much of the strength of the gas vesicle; the protein containing only two repeats binds at a lower ratio (1:7.7), however, and restores less of the strength. Ancestral proteins with only two, three or four of the 33-amino-acid repeats would have been functional in strengthening the gas vesicle but the progressive increase in number of repeats would have provided strength with increased efficiency.