Structural insights into the LCIB protein family reveals a new group of β-carbonic anhydrases.

ABSTRACT: Aquatic microalgae have evolved diverse CO₂-concentrating mechanisms (CCMs) to saturate the carboxylase with its substrate, to compensate for the slow kinetics and competing oxygenation reaction of the key photosynthetic CO₂-fixing enzyme rubisco. The limiting CO₂-inducible B protein (LCIB) is known to be essential for CCM function in Chlamydomonas reinhardtii To assign a function to this previously uncharacterized protein family, we purified and characterized a phylogenetically diverse set of LCIB homologs. Three of the six homologs are functional carbonic anhydrases (CAs). We determined the crystal structures of LCIB and limiting CO₂-inducible C protein (LCIC) from C. reinhardtii and a CA-functional homolog from Phaeodactylum tricornutum, all o

SUBMITTER: Jin S 

PROVIDER: S-EPMC5187666 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature