Open AccessStructural insights into homotrimeric assembly of cellulose synthase CesA7 from Gossypium hirsutum
Author(s) -
Zhang Xiangnan,
Xue Yuan,
Guan Zeyuan,
Zhou Chen,
Nie Yangfan,
Men She,
Wang Qiang,
Shen Cuicui,
Zhang Delin,
Jin Shuangxia,
Tu Lili,
Yin Ping,
Zhang Xianlong
Publication year - 2021
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/pbi.13571
Subject(s) - biology , transmembrane domain , microfibril , helix (gastropod) , cellulose , biochemistry , transmembrane protein , biophysics , atp synthase , membrane , gene , ecology , receptor , snail
Summary Cellulose is one of the most abundant organic polymers in nature. It contains multiple β‐1,4‐glucan chains synthesized by cellulose synthases (CesAs) on the plasma membrane of higher plants. CesA subunits assemble into a pseudo‐sixfold symmetric cellulose synthase complex (CSC), known as a ‘rosette complex’. The structure of CesA remains enigmatic. Here, we report the cryo‐EM structure of the homotrimeric CesA7 from Gossypium hirsutum at 3.5‐angstrom resolution. The GhCesA7 homotrimer shows a C3 symmetrical assembly. Each protomer contains seven transmembrane helices (TMs) which form a channel potentially facilitating the release of newly synthesized glucans. The cytoplasmic glycosyltransferase domain (GT domain) of GhCesA7 protrudes from the membrane, and its catalytic pocket is directed towards the TM pore. The homotrimer GhCesA7 is stabilized by the transmembrane helix 7 (TM7) and the plant‐conserved region (PCR) domains. It represents the building block of CSCs and facilitates microfibril formation. This structure provides insight into how eukaryotic cellulose synthase assembles and provides a mechanistic basis for the improvement of cotton fibre quality in the future.