Hsiu-Ju Chiu

Crystal structures of two novel dye-decolorizing peroxidases reveal a beta-barrel fold with a conserved heme-binding motif.

BtDyP from Bacteroides thetaiotaomicron (strain VPI‐5482) and TyrA from Shewanella oneidensis are dye‐decolorizing peroxidases (DyPs), members of a new family of heme‐dependent peroxidases recently identified in fungi and bacteria. Here, we report the crystal structures of BtDyP and TyrA at 1.6 and 2.7 Å, respectively. BtDyP assembles into a hexamer, while TyrA assembles into a dimer; the dimerization interface is conserved between the two proteins. Each monomer exhibits a two‐domain, α+β ferredoxin‐like fold. A site for heme binding was identified computationally, and modeling of a heme into the proposed active site allowed for identification of residues likely to be functionally important. Structural and sequence comparisons with other DyPs demonstrate a conservation of putative heme‐binding residues, including an absolutely conserved histidine. Isothermal titration calorimetry experiments confirm heme binding, but with a stoichiometry of 0.3:1 (heme:protein). Proteins 2007.

Structural Basis of Murein Peptide Specificity of a γ-D-glutamyl-L-diamino Acid Endopeptidase

The crystal structures of two homologous endopeptidases from cyanobacteria Anabaena variabilis and Nostoc punctiforme were determined at 1.05 and 1.60 A resolution, respectively, and contain a bacterial SH3-like domain (SH3b) and a ubiquitous cell-wall-associated NlpC/P60 (or CHAP) cysteine peptidase domain. The NlpC/P60 domain is a primitive, papain-like peptidase in the CA clan of cysteine peptidases with a Cys126/His176/His188 catalytic triad and a conserved catalytic core. We deduced from structure and sequence analysis, and then experimentally, that these two proteins act as gamma-D-glutamyl-L-diamino acid endopeptidases (EC 3.4.22.-). The active site is located near the interface between the SH3b and NlpC/P60 domains, where the SH3b domain may help define substrate specificity, instead of functioning as a targeting domain, so that only muropeptides with an N-terminal L-alanine can bind to the active site.

Crystal structure of the global regulatory protein CsrA from Pseudomonas putida at 2.05 Å resolution reveals a new fold

Chris Rife, Robert Schwarzenbacher, Daniel McMullan, Polat Abdubek, Eileen Ambing, Herbert Axelrod, Tanya Biorac, Jaume M. Canaves, Hsiu-Ju Chiu, Ashley M. Deacon, Michael DiDonato, Marc-André Elsliger, Adam Godzik, Carina Grittini, Slawomir K. Grzechnik, Joanna Hale, Eric Hampton, Gye Won Han, Justin Haugen, Michael Hornsby, Lukasz Jaroszewski, Heath E. Klock, Eric Koesema, Andreas Kreusch, Peter Kuhn, Scott A. Lesley, Mitchell D. Miller, Kin Moy, Edward Nigoghossian, Jessica Paulsen, Kevin Quijano, Ron Reyes, Eric Sims, Glen Spraggon, Raymond C. Stevens, Henry van den Bedem, Jeff Velasquez, Juli Vincent, Aprilfawn White, Guenter Wolf, Qingping Xu, Keith O. Hodgson, John Wooley, and Ian A. Wilson* The Joint Center for Structural Genomics Stanford Synchrotron Radiation Laboratory, Stanford University, Menlo Park, California The University of California, San Diego, La Jolla, California The Genomics Institute of the Novartis Research Foundation, San Diego, California The Scripps Research Institute, La Jolla, California

Crystal structure of a tandem cystathionine-β-synthase (CBS) domain protein (TM0935) from Thermotoga maritima at 1.87 Å resolution

Mitchell D. Miller, Robert Schwarzenbacher, Frank von Delft, Polat Abdubek, Eileen Ambing, Tanya Biorac, Linda S. Brinen, Jaume M. Canaves, Jamison Cambell, Hsiu-Ju Chiu, Xiaoping Dai, Ashley M. Deacon, Mike DiDonato, Marc-André Elsliger, Said Eshagi, Ross Floyd, Adam Godzik, Carina Grittini, Slawomir K. Grzechnik, Eric Hampton, Lukasz Jaroszewski, Cathy Karlak, Heath E. Klock, Eric Koesema, John S. Kovarik, Andreas Kreusch, Peter Kuhn, Scott A. Lesley, Inna Levin, Daniel McMullan, Timothy M. McPhillips, Andrew Morse, Kin Moy, Jie Ouyang, Rebecca Page, Kevin Quijano, Alyssa Robb, Glen Spraggon, Raymond C. Stevens, Henry van den Bedem, Jeff Velasquez, Juli Vincent, Xianhong Wang, Bill West, Guenter Wolf, Qingping Xu, Keith O. Hodgson, John Wooley, and Ian A. Wilson* Joint Center for Structural Genomics, Stanford Synchrotron Radiation Laboratory, Stanford University, Menlo Park California Genomics Institute of the Novartis Research Foundation, San Diego, California San Diego Supercomputer Center, La Jolla, California University of California, San Diego, La Jolla, California Scripps Research Institute, La Jolla, California

The signaling phospholipid PIP3 creates a new interaction surface on the nuclear receptor SF-1.

Significance We previously reported that lipids PI(4,5)P2 (PIP2) and PI(3,4,5)P3 (PIP3) bind NR5A nuclear receptors to regulate their activity. Here, the crystal structures of PIP2 and PIP3 bound to NR5A1 (SF-1) define a new interaction surface that is organized by the solvent-exposed PIPn headgroups. We find that stabilization by the PIP3 ligand propagates a signal that increases coactivator recruitment to SF-1, consistent with our earlier work showing that PIP3 increases SF-1 activity. This newly created surface harbors a cluster of human mutations that lead to endocrine disorders, thus explaining how these puzzling mutations cripple SF-1 activity. We propose that this new surface acts as a PIP3-regulated interface between SF-1 and coregulatory proteins, analogous to the function of membrane-bound phosphoinositides. The signaling phosphatidylinositol lipids PI(4,5)P2 (PIP2) and PI(3,4,5)P3 (PIP3) bind nuclear receptor 5A family (NR5As), but their regulatory mechanisms remain unknown. Here, the crystal structures of human NR5A1 (steroidogenic factor-1, SF-1) ligand binding domain (LBD) bound to PIP2 and PIP3 show the lipid hydrophobic tails sequestered in the hormone pocket, as predicted. However, unlike classic nuclear receptor hormones, the phosphoinositide head groups are fully solvent-exposed and complete the LBD fold by organizing the receptor architecture at the hormone pocket entrance. The highest affinity phosphoinositide ligand PIP3 stabilizes the coactivator binding groove and increases coactivator peptide recruitment. This receptor-ligand topology defines a previously unidentified regulatory protein-lipid surface on SF-1 with the phosphoinositide head group at its nexus and poised to interact with other proteins. This surface on SF-1 coincides with the predicted binding site of the corepressor DAX-1 (dosage-sensitive sex reversal, adrenal hypoplasia critical region on chromosome X), and importantly harbors missense mutations associated with human endocrine disorders. Our data provide the structural basis for this poorly understood cluster of human SF-1 mutations and demonstrates how signaling phosphoinositides function as regulatory ligands for NR5As.

Crystal structure of a PIN (PilT N‐terminus) domain (AF0591) from Archaeoglobus fulgidus at 1.90 Å resolution

Inna Levin, Robert Schwarzenbacher, Rebecca Page, Polat Abdubek, Eileen Ambing, Tanya Biorac, Linda S. Brinen, Jamison Campbell, Jaume M. Canaves, Hsiu-Ju Chiu, Xiaoping Dai, Ashley M. Deacon, Mike DiDonato, Marc-André Elsliger, Ross Floyd, Adam Godzik, Carina Grittini, Slawomir K. Grzechnik, Eric Hampton, Lukasz Jaroszewski, Cathy Karlak, Heath E. Klock, Eric Koesema, John S. Kovarik, Andreas Kreusch, Peter Kuhn, Scott A. Lesley, Daniel McMullan, Timothy M. McPhillips, Mitchell D. Miller, Andrew Morse, Kin Moy, Jie Ouyang, Kevin Quijano, Ron Reyes, Fred Rezezadeh, Alyssa Robb, Eric Sims, Glen Spraggon, Raymond C. Stevens, Henry van den Bedem, Jeff Velasquez, Juli Vincent, Frank von Delft, Xianhong Wang, Bill West, Guenter Wolf, Qingping Xu, Keith O. Hodgson, John Wooley, and Ian A. Wilson* Joint Center for Structural Genomics, Stanford Synchrotron Radiation Laboratory, Stanford University, Menlo Park California Genomics Institute of the Novartis Research Foundation, San Diego, California San Diego Supercomputer Center, La Jolla, California University of California, San Diego, La Jolla, California Scripps Research Institute, La Jolla, California

Crystal structure of acireductone dioxygenase (ARD) from Mus musculus at 2.06 Å resolution

Qingping Xu, Robert Schwarzenbacher, S. Sri Krishna, Daniel McMullan, Sanjay Agarwalla, Kevin Quijano, Polat Abdubek, Eileen Ambing, Herbert Axelrod, Tanya Biorac, Jaume M. Canaves, Hsiu-Ju Chiu, Marc-André Elsliger, Carina Grittini, Slawomir K. Grzechnik, Michael DiDonato, Joanna Hale, Eric Hampton, Gye Won Han, Justin Haugen, MichaelHornsby, Lukasz Jaroszewski, Heath E. Klock, Mark W. Knuth, Eric Koesema, Andreas Kreusch, Peter Kuhn, Mitchell D. Miller, Kin Moy, Edward Nigoghossian, Jessica Paulsen, Ron Reyes, Chris Rife, Glen Spraggon, Raymond C. Stevens, Henry van den Bedem, Jeff Velasquez, Aprilfawn White, Guenter Wolf, Keith O. Hodgson, John Wooley, Ashley M. Deacon, Adam Godzik, Scott A. Lesley, and Ian A. Wilson* The Joint Center for Structural Genomics Stanford Synchrotron Radiation Laboratory, Stanford University, Menlo Park, California The University of California San Diego, La Jolla, California The Genomics Institute of the Novartis Research Foundation, San Diego, California The Scripps Research Institute, La Jolla, California

Crystal structure of an Udp-n-acetylmuramate-alanine ligase MurC (TM0231) from Thermotoga maritima at 2.3 Å resolution

Crystal Structure of an Udp-n-acetylmuramate-alanine Ligase MurC (TM0231) from Thermotoga maritima at 2.3 Å Resolution Glen Spraggon, Robert Schwarzenbacher, Andreas Kreusch, Christian C. Lee, Polat Abdubek, Eileen Ambing, Tanya Biorac, Linda S. Brinen, Jaume M. Canaves, Jamison Cambell, Hsiu-Ju Chiu, Xiaoping Dai, Ashley M. Deacon, Mike DiDonato, Marc-André Elsliger, Said Eshagi, Ross Floyd, Adam Godzik, Carina Grittini, Slawomir K. Grzechnik, Eric Hampton, Lukasz Jaroszewski, Cathy Karlak, Heath E. Klock, Eric Koesema, John S. Kovarik, Peter Kuhn, Inna Levin, Daniel McMullan, Timothy M. McPhillips, Mitchell D. Miller, Andrew Morse, Kin Moy, Jie Ouyang, Rebecca Page, Kevin Quijano, Alyssa Robb, Raymond C. Stevens, Henry van den Bedem, Jeff Velasquez, Juli Vincent, Frank von Delft, Xianhong Wang, Bill West, Guenter Wolf, Qingping Xu, Keith O. Hodgson, John Wooley, Scott A. Lesley, and Ian A. Wilson* The Joint Center for Structural Genomics The Genomics Institute of the Novartis Research Foundation, San Diego, California 92121 The San Diego Supercomputer Center, La Jolla, California 92093 Stanford Synchrotron Radiation Laboratory, Stanford University, Menlo Park, California The Scripps Research Institute, La Jolla, California 92037 The University of California, San Diego, La Jolla, California 92093

Structural and Functional Characterizations of SsgB, a Conserved Activator of Developmental Cell Division in Morphologically Complex Actinomycetes

SsgA-like proteins (SALPs) are a family of homologous cell division-related proteins that occur exclusively in morphologically complex actinomycetes. We show that SsgB, a subfamily of SALPs, is the archetypal SALP that is functionally conserved in all sporulating actinomycetes. Sporulation-specific cell division of Streptomyces coelicolor ssgB mutants is restored by introduction of distant ssgB orthologues from other actinomycetes. Interestingly, the number of septa (and spores) of the complemented null mutants is dictated by the specific ssgB orthologue that is expressed. The crystal structure of the SsgB from Thermobifida fusca was determined at 2.6 Å resolution and represents the first structure for this family. The structure revealed similarities to a class of eukaryotic “whirly” single-stranded DNA/RNA-binding proteins. However, the electro-negative surface of the SALPs suggests that neither SsgB nor any of the other SALPs are likely to interact with nucleotide substrates. Instead, we show that a conserved hydrophobic surface is likely to be important for SALP function and suggest that proteins are the likely binding partners.

Structure of a tryptophanyl-tRNA synthetase containing an iron–sulfur cluster

The crystal structure of tryptophanyl-tRNA synthetase from T. maritima unexpectedly revealed an iron–sulfur cluster bound to the tRNA anticodon-binding region.