Polat Abdubek

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.

Structure of the γ-d-glutamyl-l-diamino acid endopeptidase YkfC from Bacillus cereus in complex with l-Ala-γ-d-Glu: insights into substrate recognition by NlpC/P60 cysteine peptidases

The crystal structure of the highly specific γ-d-glutamyl-l-diamino acid endopeptidase YkfC from Bacillus cereus in complex with l-Ala-γ-d-Glu reveals the structural basis for the substrate specificity of NlpC/P60-family cysteine peptidases.

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

Crystal Structure of the First Eubacterial Mre11 Nuclease Reveals Novel Features that May Discriminate Substrates During DNA Repair

Mre11 nuclease plays a central role in the repair of cytotoxic and mutagenic DNA double-strand breaks. As X-ray structural information has been available only for the Pyrococcus furiosus enzyme (PfMre11), the conserved and variable features of this nuclease across the domains of life have not been experimentally defined. Our crystal structure and biochemical studies demonstrate that TM1635 from Thermotoga maritima, originally annotated as a putative nuclease, is an Mre11 endo/exonuclease (TmMre11) and the first such structure from eubacteria. TmMre11 and PfMre11 display similar overall structures, despite sequence identity in the twilight zone of only approximately 20%. However, they differ substantially in their DNA-specificity domains and in their dimeric organization. Residues in the nuclease domain are highly conserved, but those in the DNA-specificity domain are not. The structural differences likely affect how Mre11 from different organisms recognize and interact with single-stranded DNA, double-stranded DNA and DNA hairpin structures during DNA repair. The TmMre11 nuclease active site has no bound metal ions, but is conserved in sequence and structure with the exception of a histidine that is important in PfMre11 nuclease activity. Nevertheless, biochemical characterization confirms that TmMre11 possesses both endonuclease and exonuclease activities on single-stranded and double-stranded DNA substrates, respectively.

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

Bacterial Pleckstrin Homology Domains: a Prokaryotic Origin for the Ph Domain

Pleckstrin homology (PH) domains have been identified only in eukaryotic proteins to date. We have determined crystal structures for three members of an uncharacterized protein family (Pfam PF08000), which provide compelling evidence for the existence of PH-like domains in bacteria (PHb). The first two structures contain a single PHb domain that forms a dome-shaped, oligomeric ring with C5 symmetry. The third structure has an additional helical hairpin attached at the C-terminus and forms a similar but much larger ring with C12 symmetry. Thus, both molecular assemblies exhibit rare, higher-order, cyclic symmetry but preserve a similar arrangement of their PHb domains, which gives rise to a conserved hydrophilic surface at the intersection of the β-strands of adjacent protomers that likely mediates protein–protein interactions. As a result of these structures, additional families of PHb domains were identified, suggesting that PH domains are much more widespread than originally anticipated. Thus, rather than being a eukaryotic innovation, the PH domain superfamily appears to have existed before prokaryotes and eukaryotes diverged.