Unique localization of the plastid-specific ribosomal proteins in the chloroplast ribosome small subunit provides mechanistic insights into the chloroplastic translation.
Unique localization of the plastid-specific ribosomal proteins in the chloroplast ribosome small subunit provides mechanistic insights into the chloroplastic translation.
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DOI：
10.1093/nar/gkx499
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发表时间：
2017-08-21
影响因子：
14.9
通讯作者：
Bhushan S
中科院分区：
文献类型：
--
作者：
Ahmed T;Shi J;Bhushan S
叶绿体翻译由细菌型70 S叶绿体核糖体介导。在进化过程中，叶绿体核糖体获得了五种叶绿体特异性核糖体蛋白（cS22，cS23，bTHXc，cL 37和cL 38），它们被认为在翻译过程中起着重要的调控作用。然而，由于缺乏高分辨率的结构，它们在叶绿体核糖体上的确切位置仍然难以捉摸，阻碍了我们了解它们可能的作用。本文报道了菠菜70 S叶绿体核糖体的冷冻电镜结构，其分辨率为3.4 × 10 - 5，并着重讨论了30 S小亚基（SSU）的结构，其分辨率为3.7 × 10 - 5。cS22定位于SSU足，在那里它似乎补偿了16 S rRNA中的缺失。由于cS23的存在，mRNA出口位点高度重塑，表明翻译起始的替代模式。bTHXc位于SSU头部，似乎在热波动期间稳定亚基间桥B1 b。翻译因子质体pY在亚基间侧与SSU结合，并与参与解码的保守核苷酸碱基相互作用。与细菌相比，大多数亚基间桥是保守的，除了涉及uL 2c和bS 6c的新桥。
Chloroplastic translation is mediated by a bacterial-type 70S chloroplast ribosome. During the evolution, chloroplast ribosomes have acquired five plastid-specific ribosomal proteins or PSRPs (cS22, cS23, bTHXc, cL37 and cL38) which have been suggested to play important regulatory roles in translation. However, their exact locations on the chloroplast ribosome remain elusive due to lack of a high-resolution structure, hindering our progress to understand their possible roles. Here we present a cryo-EM structure of the 70S chloroplast ribosome from spinach resolved to 3.4 Å and focus our discussion mainly on the architecture of the 30S small subunit (SSU) which is resolved to 3.7 Å. cS22 localizes at the SSU foot where it seems to compensate for the deletions in 16S rRNA. The mRNA exit site is highly remodeled due to the presence of cS23 suggesting an alternative mode of translation initiation. bTHXc is positioned at the SSU head and appears to stabilize the intersubunit bridge B1b during thermal fluctuations. The translation factor plastid pY binds to the SSU on the intersubunit side and interacts with the conserved nucleotide bases involved in decoding. Most of the intersubunit bridges are conserved compared to the bacteria, except for a new bridge involving uL2c and bS6c.
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影响因子：
3.7
作者：
Byrgazov K;Manoharadas S;Kaberdina AC;Vesper O;Moll I
通讯作者：
Moll I
影响因子：
7.2
作者：
Eberhard, S;Drapier, D;Wollman, FA
通讯作者：
Wollman, FA
DOI：
10.1073/pnas.85.17.6427
发表时间：
1988-09-01
影响因子：
11.1
作者：
CALOGERO, RA;PON, CL;GUALERZI, CO
通讯作者：
GUALERZI, CO
DOI：
10.1073/pnas.79.22.6871
发表时间：
1982-01-01
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
影响因子：
--
作者：
BARTSCH, M;KIMURA, M;SUBRAMANIAN, AR
通讯作者：
SUBRAMANIAN, AR
影响因子：
14.9
作者：
Drechsel O;Bock R
通讯作者：
Bock R