Protein engineering: Redirecting membrane machinery

August 18th, 2017 by Kalistyn Burley

Nature Chemical Biology 13, 927 (2017). doi:10.1038/nchembio.2451

Authors: Kalistyn Burley & Celia W Goulding

The ability to solubilize membrane proteins while retaining their native function is a persistent challenge. Re-engineering of the membrane protein DsbB into a soluble cytoplasmic version maintained its activity and enabled recompartmentalization of the periplasmic DsbAB disulfide bond–forming system.

Lysine Deacetylases Exhibit Distinct Changes in Activity Profiles Due to Fluorophore Conjugation of Substrates

August 16th, 2017 by Tasha B. Toro, Jenae R. Bryant and Terry J. Watt

TOC Graphic

DOI: 10.1021/acs.biochem.7b00270

Functional Complementation Studies Reveal Different Interaction Partners of Escherichia coli IscS and Human NFS1

August 16th, 2017 by Martin Bühning, Martin Friemel and Silke Leimkühler

TOC Graphic

DOI: 10.1021/acs.biochem.7b00627

Structural analyses of the bacterial primosomal protein DnaB reveal that it is a tetramer and forms a complex with a primosomal re-initiation protein [Protein Structure and Folding]

August 14th, 2017 by Yi-Ching Li, Vankadari Naveen, Min-Guan Lin, Chwan-Deng Hsiao

The DnaB primosomal protein from Gram-positive bacteria plays a key role in DNA replication and restart as a loader protein for the recruitment of replisome cascade proteins. Previous investigations have established that DnaB is composed of an N-terminal domain, a middle domain, and a C-terminal domain. However, structural evidence for how DnaB functions at the atomic level is lacking. Here, we report the crystal structure of DnaB, encompassing the N-terminal and middle domains (residues 1-300), from Geobacillus stearothermophilus (GstDnaB1-300) at 2.8 Å resolution. Our structure revealed that GstDnaB1-300 forms a tetramer with two basket-like architecture, a finding s consistent with those from solution studies using analytical ultracentrifugation. Furthermore, our results from both GST pull-down assays and analytical ultracentrifugation show that GstDnaB1-300 is sufficient to form a complex with PriA, the primosomal re-initiation protein. Moreover, with the aid of small angle X-ray scattering (SAXS) experiments, we also determined the structural envelope of full-length DnaB (GstDnaBFL) in solution. These SAXS studies indicated that GstDnaBFL has an elongated conformation and that the protruding density envelopes originating from GstDnaB1-300 could completely accommodate the GstDnaB C-terminal domain (residues 301-461) . Taken together with biochemical assays, our results suggest that GstDnaB uses different domains to distinguish the PriA-interaction and ssDNA-binding. This finding can further extend our understanding of primosomal assembly in replication restart.
  • Posted in Journal of Biological Chemistry, Publications
  • Comments Off on Structural analyses of the bacterial primosomal protein DnaB reveal that it is a tetramer and forms a complex with a primosomal re-initiation protein [Protein Structure and Folding]

Kinetochore regulation: Let there be light

August 14th, 2017 by Ana C Figueiredo

Nature Chemical Biology 13, 1058 (2017). doi:10.1038/nchembio.2464

Authors: Ana C Figueiredo & Helder Maiato

Kinetochores form the critical interface with spindle microtubules that accounts for chromosome movement and segregation fidelity during mitosis. Spatial and temporal control of motor protein and checkpoint signaling at kinetochores is now possible with a new set of optogenetic tools.

Optogenetic control of kinetochore function

August 14th, 2017 by Huaiying Zhang

Nature Chemical Biology 13, 1096 (2017). doi:10.1038/nchembio.2456

Authors: Huaiying Zhang, Chanat Aonbangkhen, Ekaterina V Tarasovetc, Edward R Ballister, David M Chenoweth & Michael A Lampson

Small-molecule studies identify CDK8 as a regulator of IL-10 in myeloid cells

August 14th, 2017 by Liv Johannessen

Nature Chemical Biology 13, 1102 (2017). doi:10.1038/nchembio.2458

Authors: Liv Johannessen, Thomas B Sundberg, Daniel J O'Connell, Raivo Kolde, James Berstler, Katelyn J Billings, Bernard Khor, Brinton Seashore-Ludlow, Anne Fassl, Caitlin N Russell, Isabel J Latorre, Baishan Jiang, Daniel B Graham, Jose R Perez, Piotr Sicinski, Andrew J Phillips, Stuart L Schreiber, Nathanael S Gray, Alykhan F Shamji & Ramnik J Xavier

  • Posted in Nat Chem Biol, Publications
  • Comments Off on Small-molecule studies identify CDK8 as a regulator of IL-10 in myeloid cells

Engineering Aromatic–Aromatic Interactions To Nucleate Folding in Intrinsically Disordered Regions of Proteins

August 11th, 2017 by Swati Balakrishnan and Siddhartha P. Sarma

TOC Graphic

DOI: 10.1021/acs.biochem.7b00437

Fibronectin Conformation and Assembly: Analysis of Fibronectin Deletion Mutants and Fibronectin Glomerulopathy (GFND) Mutants

August 10th, 2017 by Tomoo Ohashi, Christopher A. Lemmon and Harold P. Erickson

TOC Graphic

DOI: 10.1021/acs.biochem.7b00589

Mapping Functionally Important Residues in the Na+/Dicarboxylate Cotransporter, NaDC1

August 10th, 2017 by Claire Colas, Avner Schlessinger and Ana M. Pajor

TOC Graphic

DOI: 10.1021/acs.biochem.7b00503