On April 11,Nature Communicationspublished online a paper entitled "Cryo-EM structures of mitochondrial ABC transporter ABCB10 in apo and biliverdin-bound form" by Professor OUYANG Zhuqing's team from School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology. The study reports the cryo-EM structures of mitochondrial ABC transporter ABCB10 in apo and biliverdin-bound form at 3.67 Å and 2.85 Å resolution, respectively. apo) and the cryo-electron microscopic structures of the cholestin-bound form ABCB10 (ABCB10-BV), respectively.

ABCB10, a member of ABC transporter superfamily that locates in the inner membrane of mitochondria, plays crucial roles in hemoglobin synthesis, antioxidative stress and stabilization of the iron transporter mitoferrin-1. Recently, it was found that ABCB10 is a mitochondrial biliverdin exporter. However, the molecular mechanism of biliverdin export by ABCB10 remains elusive. Here we report the cryo-EM structures of ABCB10 in apo (ABCB10-apo) and biliverdin-bound form (ABCB10-BV) at 3.67 Å and 2.85 Å resolution, respectively. ABCB10-apo adopts a wide-open conformation and may thus represent the apo form structure. ABCB10-BV forms a closed conformation and biliverdin situates in a hydrophobic pocket in one protomer and bridges the interaction through hydrogen bonds with the opposing one. We also identify cholesterols sandwiched by BVs and discuss the export dynamics based on these structural and biochemical observations.

Authors and Affiliations

1.Wuxi Biortus Biosciences Co. Ltd., 6 Dongsheng Western Road, 214437, Jiangyin, Jiangsu, China

Sheng Cao, Yihu Yang, Xiaodong Yan, Hui Shi & Jiaquan Wu

2.Department of Pathogen Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, 430030, Wuhan, Hubei Province, China

Lili He, Yumo Hang & Zhuqing Ouyang

Contributions

S.C.,Y.Y., X.Y., and H.S. devised the methodology; S.C., Y.Y., L.H., Y.H., X.Y., and H.S. performed the investigation; J.W. and Z.O. acquired the funding and supervised the project; S.C., Y.Y., L.H., J.W., and Z.O. wrote the paper with input from all authors.

Paper link：Cryo-EM structures of mitochondrial ABC transporter ABCB10 in apo and biliverdin-bound form | Nature Communications