Environmental Adaption of Rubisco in Global Marine Systems
I.J. HOPE, G.S. CALDWELL, J. TELLING, M. V. KAPRALOV
School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne, UK, NE1 7RU

Marine environments are responsible for 50% of the net primary fixation of carbon globally. Predominantly, the Calvin Benson Basham cycle fixes carbon with the initial enzyme being Rubisco. Rubisco has been shown to be a significant bottleneck in photosynthesis, due to a slow catalytic rate and promiscuity of the enzyme. Previous Rubisco studies have largely focused on land plants, and little is known about the diversity and abundance of Rubisco within marine environments. Through analysing publicly available metagenomes and metatranscriptomes from the Earth’s seas and oceans; we have begun to paint a picture of the global abundance and variation of Rubisco. On top of this, sequence analysis of Rubisco structures provides evidence for adaption of the large and small subunit to differing environments, highlighting residues that diverge in tropical and polar systems. This study expands our knowledge of the Rubisco sequence space and presents opportunities for future engineering projects in economically important plants.