Purification, characterisation and preliminary structural study of low-carbon dioxide-inducible proteins LCIB and LCIC in Chlamydomonas reinhardtii

• Main Author: Jin, Shengyang
• Other Authors: Yonggui Gao
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Science::Biological sciences::Molecular biology
• Online Access: http://hdl.handle.net/10356/61909
• Institution: Nanyang Technological University

Carbon concentrating mechanism (CCM) ensures the necessary efficiency of photosynthesis in aquatic green alga Chlamydomonas reinhardtii. At ambient carbon dioxide level, LCIB mutant strain has its intracellular inorganic carbon accumulation almost completely compromised, and therefore the CCM is effectively abolished. It has been suggested that LCIB forms a large oligomeric complex with its homologous protein LCIC and therefore may exert their function in the complex form. In this study, we subjected different constructs of heterogeneously expressed LCIB/LCIC subunits and complexes to various analyses including crystallisation screening, electron microscopy, multiple-angle light scattering and analytical size-exclusion chromatography to determine their biochemical properties and preliminary structure. We discovered that the LCIB and LCIC subunits formed pentamer and dimer respectively, and the complex consisted of four LCIB and LCIC subunits each, arranged in an octamer. The possible low resolution EM structure of the complex and some crystallisation hits of LCIC were also obtained. Our results provide a critical basis towards structural targets of LCIB, LCIC and their complex