LCIB functions as a carbonic anhydrase: evidence from yeast and Arabidopsis carbonic anhydrase knockout mutants.
Photosynth Res
; 156(2): 193-204, 2023 May.
Article
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| MEDLINE
| ID: mdl-36856938
Chlamydomonas reinhardtii evolved a CO2-concentrating mechanism (CCM) because of the limited CO2 in its natural environment. One critical component of the C. reinhardtii CCM is the limiting CO2 inducible B (LCIB) protein. LCIB is required for acclimation to air levels of CO2. C. reinhardtii cells with a mutated LCIB protein have an 'air-dier' phenotype when grown in low CO2 conditions, meaning they die in air levels of CO2 but can grow in high and very low CO2 conditions. The LCIB protein functions together with its close homolog in C. reinhardtii, limiting CO2 inducible C protein (LCIC), in a hexameric LCIB-LCIC complex. LCIB has been proposed to act as a vectoral carbonic anhydrase (CA) that helps to recapture CO2 that would otherwise leak out of the chloroplast. Although both LCIB and LCIC are structurally similar to ßCAs, their CA activity has not been demonstrated to date. We provide evidence that LCIB is an active CA using a Saccharomyces cerevisiae CA knockout mutant (∆NCE103) and an Arabidopsis thaliana ßCA5 knockout mutant (ßca5). We show that different truncated versions of the LCIB protein complement ∆NCE103, while the full length LCIB protein complements ßca5 plants, so that both the yeast and plant mutants can grow in low CO2 conditions.
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1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Chlamydomonas reinhardtii
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Anhidrasas Carbónicas
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Arabidopsis
Idioma:
En
Revista:
Photosynth Res
Asunto de la revista:
METABOLISMO
Año:
2023
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Países Bajos