07.05.2013 | Youngchang Kim; Zi Ye; Grazyna Joachimiak; Patrick Videau; Jasmine Young; Kathryn Hurd; Sean M. Callahan; Piotr Gorn ..., Proceedings of the National Academy of Sciences current issue, 2013

HetR is an essential regulator of heterocyst development in cyanobacteria. Many mutations in HetR render Anabaena incapable of nitrogen fixation. The protein binds to a DNA palindrome upstream of hetP and other genes. We have determined the crystal structures of HetR complexed with ...

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07.05.2013 | Matthew B. Lohse; Aaron D. Hernday; Polly M. Fordyce; Liron Noiman; Trevor R. Sorrells; Victor Hanson-Smith; Clariss ..., Proceedings of the National Academy of Sciences current issue, 2013

Sequence-specific DNA-binding proteins are among the most important classes of gene regulatory proteins, controlling changes in transcription that underlie many aspects of biology. In this work, we identify a transcriptional regulator from the human fungal pathogen Candida albicans that binds ...

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07.05.2013 | Jian Li; Donald L. Holzschu; Tomohiko Sugiyama, Proceedings of the National Academy of Sciences current issue, 2013

Proliferating cell nuclear antigen (PCNA) is required for DNA homologous recombination (HR), but its exact role is unclear. Here, we investigated the loading of PCNA onto a synthetic D-loop (DL) intermediate of HR and the functional interactions of PCNA with Rad51 recombinase and DNA ...

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30.04.2013 | Neha Garg; Luis M. A. Salazar-Ocampo; Wilfred A. van der Donk, Proceedings of the National Academy of Sciences current issue, 2013

The biosynthesis of several classes of ribosomally synthesized and posttranslationally modified peptides involves dehydration of serine and threonine residues. For class I lantibiotics, thiopeptides, and goadsporin, this dehydration is catalyzed by lanthionine biosynthetic enzyme B (LanB) or ...

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30.04.2013 | Jennifer L. Gallop; Astrid Walrant; Lewis C. Cantley; Marc W. Kirschner, Proceedings of the National Academy of Sciences current issue, 2013

The membrane–cytosol interface is the major locus of control of actin polymerization. At this interface, phosphoinositides act as second messengers to recruit membrane-binding proteins. We show that curved membranes, but not flat ones, can use phosphatidylinositol 3-phosphate [PI(3)P] along ...

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30.04.2013 | Juan Reguera; Hélène Malet; Friedemann Weber; Stephen Cusack, Proceedings of the National Academy of Sciences current issue, 2013

The nucleoprotein (NP) of segmented negative-strand RNA viruses such as Orthomyxo-, Arena-, and Bunyaviruses coats the genomic viral RNA and together with the polymerase forms ribonucleoprotein particles (RNPs), which are both the template for replication and transcription and are packaged ...

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30.04.2013 | Fan Zhang; Patrick Scheerer; Inga Oberpichler; Tilman Lamparter; Norbert Krauß, Proceedings of the National Academy of Sciences current issue, 2013

The (6-4) photolyases use blue light to reverse UV-induced (6-4) photoproducts in DNA. This (6-4) photorepair was thought to be restricted to eukaryotes. Here we report a prokaryotic (6-4) photolyase, PhrB from Agrobacterium tumefaciens, and propose that (6-4) photolyases are broadly ...

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30.04.2013 | Xuehong Yu; Tom C. M. Seegar; Annamarie C. Dalton; Dorothea Tzvetkova-Robev; Yehuda Goldgur; Kanagalaghatta R. Rajas ..., Proceedings of the National Academy of Sciences current issue, 2013

Angiogenesis is a complex cellular process involving multiple regulatory growth factors and growth factor receptors. Among them, the ligands for the endothelial-specific tunica intima endothelial receptor tyrosine kinase 2 (Tie2) receptor kinase, angiopoietin-1 (Ang1) and Ang2, play essential ...

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30.04.2013 | Joseph M. Muretta; Karl J. Petersen; David D. Thomas, Proceedings of the National Academy of Sciences current issue, 2013

We have used transient kinetics, nanosecond time-resolved fluorescence resonance energy transfer (FRET), and kinetics simulations to resolve a structural transition in the Dictyostelium myosin II relay helix during the actin-activated power stroke. The relay helix plays a critical role in ...

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30.04.2013 | Smriti Priya; Sandeep Kumar Sharma; Vishal Sood; Rayees U. H. Mattoo; Andrija Finka; Abdussalam Azem; Paolo De Los R ..., Proceedings of the National Academy of Sciences current issue, 2013

Chaperonins are cage-like complexes in which nonnative polypeptides prone to aggregation are thought to reach their native state optimally. However, they also may use ATP to unfold stably bound misfolded polypeptides and mediate the out-of-cage native refolding of large proteins. Here, we ...

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