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Your search keyword '"Cheng, Ji"' showing total 11 results
Start Over Author "Cheng, Ji" Journal nature communications
11 results on '"Cheng, Ji"'

5. Dynamic-quenching of a single-photon avalanche photodetector using an adaptive resistive switch

Author

Jiyuan Zheng, Xingjun Xue, Cheng Ji, Yuan Yuan, Keye Sun, Daniel Rosenmann, Lai Wang, Jiamin Wu, Joe C. Campbell, and Supratik Guha

Subjects
Science
Abstract

The limited recovery speed of the single-photon avalanche diodes due to the passive resistor in series strongly reduces the detector’s frequency response. Here Zheng et al., overcome this problem by using an adaptive resistive switch and reaching an avalanche pulse width as small as 30 ns.

Published
2022
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10. Rhodobacter capsulatus forms a compact crescent-shaped LH1–RC photocomplex

Author

Kazutoshi Tani, Ryo Kanno, Xuan-Cheng Ji, Itsusei Satoh, Yuki Kobayashi, Malgorzata Hall, Long-Jiang Yu, Yukihiro Kimura, Akira Mizoguchi, Bruno M. Humbel, Michael T. Madigan, and Zheng-Yu Wang-Otomo

Subjects
Multidisciplinary, General Physics and Astronomy, General Chemistry, General Biochemistry, Genetics and Molecular Biology
Abstract

Rhodobacter (Rba.) capsulatus has been a favored model for studies of all aspects of bacterial photosynthesis. This purple phototroph contains PufX, a polypeptide crucial for dimerization of the light-harvesting 1–reaction center (LH1–RC) complex, but lacks protein-U, a U-shaped polypeptide in the LH1–RC of its close relative Rba. sphaeroides. Here we present a cryo-EM structure of the Rba. capsulatus LH1–RC purified by DEAE chromatography. The crescent-shaped LH1–RC exhibits a compact structure containing only 10 LH1 αβ-subunits. Four αβ-subunits corresponding to those adjacent to protein-U in Rba. sphaeroides were absent. PufX in Rba. capsulatus exhibits a unique conformation in its N-terminus that self-associates with amino acids in its own transmembrane domain and interacts with nearby polypeptides, preventing it from interacting with proteins in other complexes and forming dimeric structures. These features are discussed in relation to the minimal requirements for the formation of LH1–RC monomers and dimers, the spectroscopic behavior of both the LH1 and RC, and the bioenergetics of energy transfer from LH1 to the RC.

Published
2023

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