Structural insights into the LCIB protein family reveals a new group of ß-carbonic anhydrases.
Proc Natl Acad Sci U S A
; 113(51): 14716-14721, 2016 12 20.
Article
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| MEDLINE
| ID: mdl-27911826
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 of which harbor motifs bearing close resemblance to the active site of canonical ß-CAs. Our results identify the LCIB family as a previously unidentified group of ß-CAs, and provide a biochemical foundation for their function in the microalgal CCMs.
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1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Fotosíntesis
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Proteínas de Plantas
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Dióxido de Carbono
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Chlamydomonas reinhardtii
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Anhidrasas Carbónicas
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Año:
2016
Tipo del documento:
Article