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Crystal structures of two tetrameric β‐carbonic anhydrases from the filamentous ascomycete Sordaria macrospora
Author(s) -
Lehneck Ronny,
Neumann Piotr,
Vullo Daniela,
Elleuche Skander,
Supuran Claudiu T.,
Ficner Ralf,
Pöggeler Stefanie
Publication year - 2014
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/febs.12738
Subject(s) - crystallography , chemistry , protein data bank (rcsb pdb) , crystal structure , bicarbonate , active site , molecule , enzyme , stereochemistry , biochemistry , organic chemistry
Carbonic anhydrases ( CA s) are metalloenzymes catalyzing the reversible hydration of carbon dioxide to bicarbonate (hydrogen carbonate) and protons. CA s have been identified in archaea, bacteria and eukaryotes and can be classified into five groups (α, β, γ, δ, ζ) that are unrelated in sequence and structure. The fungal β‐class has only recently attracted attention. In the present study, we investigated the structure and function of the plant‐like β‐ CA proteins CAS 1 and CAS 2 from the filamentous ascomycete Sordaria macrospora . We demonstrated that both proteins can substitute for the Saccharomyces cerevisiae β‐ CA Nce103 and exhibit an in vitro CO 2 hydration activity ( k cat / K m of CAS 1: 1.30 × 10 6 m −1 ·s −1 ; CAS 2: 1.21 × 10 6 m −1 ·s −1 ). To further investigate the structural properties of CAS 1 and CAS 2, we determined their crystal structures to a resolution of 2.7 Å and 1.8 Å, respectively. The oligomeric state of both proteins is tetrameric. With the exception of the active site composition, no further major differences have been found. In both enzymes, the Zn 2 + ‐ion is tetrahedrally coordinated; in CAS 1 by Cys45, His101 and Cys104 and a water molecule and in CAS 2 by the side chains of four residues (Cys56, His112, Cys115 and Asp58). Both CA s are only weakly inhibited by anions, making them good candidates for industrial applications. Structured digital abstractCAS1 and CAS2 bind by x-ray crystallography ( View interaction )Database Structural data have been deposited in the Protein Data Bank database under accession numbers 4O1J for CAS1 and 4O1K for CAS2.