5B5Z

Crystal structure of PtLCIB4 H88A mutant, a homolog of the limiting CO2-inducible protein LCIB

Summary for 5B5Z

• Entry DOI: 10.2210/pdb5b5z/pdb
• Related: 5B5X 5B5Y 5B60 5K5W
• Descriptor: PtLCIB4 H88A mutant, ZINC ION (3 entities in total)
• Functional Keywords: metalloenzyme, metal binding protein
• Biological source: Phaeodactylum tricornutum
• Total number of polymer chains: 2
• Total formula weight: 60612.43

Authors

Jin, S.,Sun, J.,Wunder, T.,Tang, D.,Mueller-Caja, O.M.,Gao, Y. (deposition date: 2016-05-24, release date: 2016-12-07, Last modification date: 2023-11-08)

Primary citation

Jin, S.,Sun, J.,Wunder, T.,Tang, D.,Cousins, A.B.,Sze, S.K.,Mueller-Cajar, O.,Gao, Y.G.
Structural insights into the LCIB protein family reveals a new group of beta-carbonic anhydrases
Proc. Natl. Acad. Sci. U.S.A., 113:14716-14721, 2016

PubMed Abstract: Aquatic microalgae have evolved diverse CO-concentrating mechanisms (CCMs) to saturate the carboxylase with its substrate, to compensate for the slow kinetics and competing oxygenation reaction of the key photosynthetic CO-fixing enzyme rubisco. The limiting CO-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 CO-inducible C protein (LCIC) from C. reinhardtii and a CA-functional homolog from Phaeodactylum tricornutum, all of which harbor motifs bearing close resemblance to the active site of canonical β-CAs. Our results identify the LCIB family as a previously unidentified group of β-CAs, and provide a biochemical foundation for their function in the microalgal CCMs.

PubMed: 27911826
DOI: 10.1073/pnas.1616294113

Experimental method

X-RAY DIFFRACTION (1.6 Å)