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Crystal structure of an assembly intermediate of respiratory Complex II
Author(s) -
Sharma Pankaj,
Maklashina Elena,
Cecchini Gary,
Iverson Tina
Publication year - 2018
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2018.32.1_supplement.lb41
Subject(s) - covalent bond , protein subunit , chemistry , cofactor , structural biology , flavin group , conformational change , crystallography , protein structure , biophysics , stereochemistry , biology , biochemistry , enzyme , gene , organic chemistry
In approximately 10% of flavoenzymes, the flavin is covalently attached. Despite the importance of this covalent cofactor for a number of biological functions, the mechanism of covalent flavinylation is currently poorly understood. In this work, we determined the crystal structure of a captured assembly intermediate of covalent flavinylation using the Escherichia coli Complex II FrdA subunit crosslinked with its assembly factor, SdhE. Two global conformational changes in FrdA subunit were observed as compared to prior structures of the assembled Complex II protein: rotation of the capping domain, and the destabilization of two large loops proximal to the active site of the FrdA subunit. Together, these changes create a tunnel to the active site. This FrdA‐SdhE structure was used as a basis to develop a mechanism of covalent flavinylation that is supported by spectroscopic and kinetic analyses. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .