A 30-RESIDUE-LONG EXPORT INITIATION DOMAIN ADJACENT TO THE SIGNAL SEQUENCE IS CRITICAL FOR PROTEIN TRANSLOCATION ACROSS THE INNER MEMBRANE OF ESCHERICHIA-COLI
A 30-RESIDUE-LONG EXPORT INITIATION DOMAIN ADJACENT TO THE SIGNAL SEQUENCE IS CRITICAL FOR PROTEIN TRANSLOCATION ACROSS THE INNER MEMBRANE OF ESCHERICHIA-COLI
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DOI：
10.1073/pnas.88.21.9751
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发表时间：
1991-11-01
影响因子：
11.1
通讯作者：
VONHEIJNE, G
中科院分区：
文献类型：
--
作者：
ANDERSSON, H;VONHEIJNE, G
信号序列用于将蛋白质靶向至原核和真核细胞中的分泌途径。然而，尽管必要，信号序列的存在并不总是足以确保有效的膜易位。至少在大肠杆菌中，对分泌产生不利影响的新生链的一个特征是在信号序列的紧下游存在带正电荷的氨基酸。我们已经利用这种敏感性带正电荷的残基，以证明存在一个明确界定的“出口起始域”，包括信号序列和它的几乎等于30个下游残基。一串六个连续的赖氨酸完全阻断易位时，放置在这个结构域内，但不是当放置只有几个残基更远。
Signal sequences serve to target proteins to the secretory pathway in both prokaryotic and eukaryotic cells. However, although necessary, the presence of a signal sequence is not always sufficient to ensure efficient membrane translocation. One feature of the nascent chain that adversely affects secretion, at least in Escherichia coli, is the presence of positively charged amino acids immediately downstream of the signal sequence. We have exploited this sensitivity to positively charged residues to demonstrate the presence of a sharply delimited "export initiation domain" that comprises the signal sequence and its almost-equal-to 30 downstream residues. A string of six consecutive lysines completely blocks translocation when placed inside this domain but not when placed only a few residues further away.