Crystal structure of pentameric shell protein CsoS4B of Halothiobacillus neapolitanus α-carboxysome

Yan-Yan Zhao; Yong-Liang Jiang; Yuxing Chen; Cong-Zhao Zhou; Qiong Li

doi:10.1016/j.bbrc.2019.05.047

Crystal structure of pentameric shell protein CsoS4B of Halothiobacillus neapolitanus α-carboxysome

Biochem Biophys Res Commun. 2019 Jul 30;515(3):510-515. doi: 10.1016/j.bbrc.2019.05.047. Epub 2019 Jun 3.

Authors

Yan-Yan Zhao¹, Yong-Liang Jiang¹, Yuxing Chen¹, Cong-Zhao Zhou², Qiong Li³

Affiliations

¹ Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China.
² Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China. Electronic address: zcz@ustc.edu.cn.
³ Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China. Electronic address: liqiong@ustc.edu.cn.

PMID: 31171360
DOI: 10.1016/j.bbrc.2019.05.047

Abstract

Carboxysome, encapsulating an enzymatic core within an icosahedral-shaped semipermeable protein shell, could enhance CO₂ fixation under low CO₂ conditions in the environment. The shell of Halothiobacillus neapolitanus α-carboxysome possesses two 38% sequence-identical pentameric proteins, namely CsoS4A and CsoS4B. However, the functions of two paralogous pentameric proteins in α-carboxysome assembly remain unknown. Here we report the crystal structure of CsoS4B at 2.15 Å resolution. It displays as a stable pentamer, each subunit of which consists of a β-barrel core domain, in addition to an insertion of helix α1 that forms the central pore. Structural comparisons and multiple-sequence alignment strongly indicate that CsoS4A and CsoS4B differ from each other in interacting with various components of α-carboxysome, despite they share a similar overall structure. These findings provide the structural basis for further investigations on the self-assembly process of carboxysome.

Keywords: Crystal structure; CsoS4B; Electrostatic potential; Pentameric protein; α-Carboxysome.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Amino Acid Sequence
Bacterial Proteins / chemistry*
Crystallography, X-Ray
Halothiobacillus / chemistry*
Models, Molecular
Protein Multimerization*
Static Electricity
Structural Homology, Protein

Substances

Bacterial Proteins