Ultra–high‐resolution structure and charge‐density analysis of high‐potential iron–sulfur protein

Abstract

The high-potential iron-sulfur protein (HiPIP) is a small (~80 residues) soluble metalloprotein functioning as an electron carrier in photosynthetic bacteria. HiPIP has one Fe 4 S 4 cluster at its molecular center. Its electronic structure is important for understanding electron transport. We recently succeeded in determining an ultra-high-resolution structure and analyzing the charge-density of HiPIP by using X-ray diffraction data at 0.48 A resolution. The distribution of valence electrons in the iron-sulfur cluster and in the protein environment were clearly visualized, which is the first successful case for metalloproteins. In addition, a topological analysis of the charge density provided information about the electronic structure of the cluster.

New insights into the oxidation process from neutron and X-ray crystal structures of an O2-sensitive [NiFe]-hydrogenase

“…High-potential iron-sulfur proteins (HiPIPs) are among the most well structurally characterized [4Fe-4S]-type clusters. 41,42 Typically, HiPIPs have one [4Fe-4S] cluster, with the (+3/+2) redox pair providing a redox potential of z+350 mV. 43,44 This is fundamentally different from the redox potential of <−300 mV for the proximal cluster with the (+2/+1) redox pair in DvMF-H 2 ase.…”

A guide to sample delivery systems for serial crystallography

“…The structure determination of biomacromolecules and their complexes is a very important part of structural biology. The structural information of biomacromolecules and their complexes is very fundamental for understanding the nature of life . Therefore, it is of great scientific significance and practical value to study the structure and function of biomacromolecules and their complexes, such as enzymes.…”