Structural and biochemical characterization of novel carbonic anhydrases from Phaeodactylum tricornutum.
Acta Crystallogr D Struct Biol
; 76(Pt 7): 676-686, 2020 Jul 01.
Article
in En
| MEDLINE
| ID: mdl-32627740
ABSTRACT
Carbonic anhydrases (CAs) are a well characterized family of metalloenzymes that are highly efficient in facilitating the interconversion between carbon dioxide and bicarbonate. Recently, CA activity has been associated with the LCIB (limiting CO2-inducible protein B) protein family, which has been an interesting target in aquatic photosynthetic microorganisms. To gain further insight into the catalytic mechanism of this new group of CAs, the X-ray structure of a highly active LCIB homolog (PtLCIB3) from the diatom Phaeodactylum tricornutum was determined. The CA activities of PtLCIB3, its paralog PtLCIB4 and a variety of their mutants were also measured. It was discovered that PtLCIB3 has a classic ß-CA fold and its overall structure is highly similar to that of its homolog PtLCIB4. Subtle structural alterations between PtLCIB3 and PtLCIB4 indicate that an alternative proton-shuttle cavity could perhaps be one reason for their remarkable difference in CA activity. A potential alternative proton-shuttle route in the LCIB protein family is suggested based on these results.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Carbonic Anhydrases
/
Diatoms
Language:
En
Journal:
Acta Crystallogr D Struct Biol
Year:
2020
Document type:
Article
Affiliation country:
Singapur