MultiBac: expanding the research toolbox for multiprotein complexes

This article is made available for unrestricted research re-use and secondary analysis in any form or by any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.Protein complexes composed of many subunits carry out most essential processes in cells and, therefore, have become the focus of intense research. However, deciphering the structure and function of these multiprotein assemblies imposes the challenging task of producing them in sufficient quality and quantity. To overcome this bottleneck, powerful recombinant expression technologies are being developed. In this review, we describe the use of one of these technologies, MultiBac, a baculovirus expression vector system that is particularly tailored for the production of eukaryotic multiprotein complexes. Among other applications, MultiBac has been used to produce many important proteins and their complexes for their structural characterization, revealing fundamental cellular mechanisms

Glutathione-conjugating and membrane-remodeling activity of GDAP1 relies on amphipathic C-terminal domain

Mutations in the ganglioside-induced differentiation associated protein 1 (GDAP1) cause severe peripheral motor and sensory neuropathies called Charcot-Marie-Tooth disease. GDAP1 expression induces fission of mitochondria and peroxisomes by a currently elusive mechanism, while disease causing mutations in GDAP1 impede the protein’s role in mitochondrial dynamics. In silico analysis reveals sequence similarities of GDAP1 to glutathione S-transferases (GSTs). However, a proof of GST activity and its possible impact on membrane dynamics are lacking to date. Using recombinant protein, we demonstrate for the first time theta-class-like GST activity for GDAP1, and it’s activity being regulated by the C-terminal hydrophobic domain 1 (HD1) of GDAP1 in an autoinhibitory manner. Moreover, we show that the HD1 amphipathic pattern is required to induce membrane dynamics by GDAP1. As both, fission and GST activities of GDAP1, are critically dependent on HD1, we propose that GDAP1 undergoes a molecular switch, turning from a pro-fission active to an auto-inhibited inactive conformation.ISSN:2045-232

Getting a Grip on Complexes

We are witnessing tremendous advances in our understanding of the organization of life. Complete genomes are being deciphered with ever increasing speed and accuracy, thereby setting the stage for addressing the entire gene product repertoire of cells, towards understanding whole biological systems. Advances in bioinformatics and mass spectrometric techniques have revealed the multitude of interactions present in the proteome. Multiprotein complexes are emerging as a paramount cornerstone of biological activity, as many proteins appear to participate, stably or transiently, in large multisubunit assemblies. Analysis of the architecture of these assemblies and their manifold interactions is imperative for understanding their function at the molecular level. Structural genomics efforts have fostered the development of many technologies towards achieving the throughput required for studying system-wide single proteins and small interaction motifs at high resolution. The present shift in focus towards large multiprotein complexes, in particular in eukaryotes, now calls for a likewise concerted effort to develop and provide new technologies that are urgently required to produce in quality and quantity the plethora of multiprotein assemblies that form the complexome, and to routinely study their structure and function at the molecular level. Current efforts towards this objective are summarized and reviewed in this contribution

Nucleic Acid Science – The Excitement of Discovery: Annual Symposium of the Chemical Society Zürich CGZ, Zürich, October 26, 2007: Conference Reports

The Chemical Society Zürich held its annual symposium on frontiers in nucleic acid science at the Eidgenössische Technische Hochschule Zürich. The conference successfully bridged nucleic acid chemistry and biology, with topics including new developments in DNA nanotechnology, mechanisms of gene transactivation by a left-handed form of DNA, chemical catalysis by RNA enzymes, state-of-the art developments in mass spectrometry of RNA–protein complexes and structural analysis of gene transcription by a large multisubunit RNA polymerase enzyme

The Crystal Structure of the Carboxy-Terminal Domain of Human Translation Initiation Factor eIF5

The carboxy-terminal domain (CTD) of eukaryotic initiation factor 5 (eIF5) plays a central role in the formation of the multifactor complex (MFC), an important intermediate for the 43 S preinitiation complex assembly. The IF5-CTD interacts directly with the translation initiation factors eIF1, eIF2-β, and eIF3c, thus forming together with eIF2 bound Met-tRNAi Met the MFC. In this work we present the high resolution crystal structure of eIF5-CTD. This domain of the protein is exclusively composed out of alpha-helices and is homologous to the carboxy-terminal domain of eIF2B-ε (eIF2Bε-CTD). The most striking difference in the two structures is an additional carboxy-terminal helix in eIF5. The binding sites of eIF2-β, eIF3 and eIF1 were mapped onto the structure. eIF2-β and eIF3 bind to non-overlapping patches of negative and positive electrostatic potential, respectively. © 2006 Elsevier Ltd. All rights reserved.This work has been supported by the Swiss National Science Foundation and the Berner Hochschulstiftung. We gratefully acknowledge the help of Clemens Schulze-Briese at beamline X06SA, SLS, PSI Villigen, Martin Walsh at beamline BM14, ESRF, Grenoble, and Gordon Leonard at ID29, ESRF, GrenoblePeer Reviewe

Multiprotein Expression Strategy for Structural Biology of Eukaryotic Complexes

SummaryThe concept of the cell as a collection of multisubunit protein machines is emerging as a cornerstone of modern biology, and molecular-level study of these machines in most cases will require recombinant production. Here, we present and validate a strategy to rapidly produce, permutate, and posttranslationally modify large, eukaryotic multiprotein complexes by using DNA recombination in a process that is fully automatable. Parallel production of 12 protein complex variants within a period of weeks resulted in specimens of sufficient quantity and homogeneity for structural biology applications