Structural basis for the initiation of eukaryotic transcription-coupled DNA repair

Eukaryotic transcription-coupled repair (TCR) is an important and well-conserved sub-pathway of nucleotide excision repair that preferentially removes DNA lesions from the template strand that block translocation of RNA polymerase II (Pol II). Cockayne syndrome group B (CSB, also known as ERCC6) protein in humans (or its yeast orthologues, Rad26 in Saccharomyces cerevisiae and Rhp26 in Schizosaccharomyces pombe) is among the first proteins to be recruited to the lesion-arrested Pol II during the initiation of eukaryotic TCR. Mutations in CSB are associated with the autosomal-recessive neurological disorder Cockayne syndrome, which is characterized by progeriod features, growth failure and photosensitivity1. The molecular mechanism of eukaryotic TCR initiation remains unclear, with several long-standing unanswered questions. How cells distinguish DNA lesion-arrested Pol II from other forms of arrested Pol II, the role of CSB in TCR initiation, and how CSB interacts with the arrested Pol II complex are all unknown. The lack of structures of CSB or the Pol II–CSB complex has hindered our ability to address these questions. Here we report the structure of the S. cerevisiae Pol II–Rad26 complex solved by cryo-electron microscopy. The structure reveals that Rad26 binds to the DNA upstream of Pol II, where it markedly alters its path. Our structural and functional data suggest that the conserved Swi2/Snf2-family core ATPase domain promotes the forward movement of Pol II, and elucidate key roles for Rad26 in both TCR and transcription elongation

Structural basis for the initiation of eukaryotic transcription-coupled DNA repair

Eukaryotic transcription-coupled repair (TCR) is an important and well-conserved sub-pathway of nucleotide excision repair that preferentially removes DNA lesions from the template strand that block translocation of RNA polymerase II (Pol II). Cockayne syndrome group B (CSB, also known as ERCC6) protein in humans (or its yeast orthologues, Rad26 in Saccharomyces cerevisiae and Rhp26 in Schizosaccharomyces pombe) is among the first proteins to be recruited to the lesion-arrested Pol II during the initiation of eukaryotic TCR. Mutations in CSB are associated with the autosomal-recessive neurological disorder Cockayne syndrome, which is characterized by progeriod features, growth failure and photosensitivity1. The molecular mechanism of eukaryotic TCR initiation remains unclear, with several long-standing unanswered questions. How cells distinguish DNA lesion-arrested Pol II from other forms of arrested Pol II, the role of CSB in TCR initiation, and how CSB interacts with the arrested Pol II complex are all unknown. The lack of structures of CSB or the Pol II–CSB complex has hindered our ability to address these questions. Here we report the structure of the S. cerevisiae Pol II–Rad26 complex solved by cryo-electron microscopy. The structure reveals that Rad26 binds to the DNA upstream of Pol II, where it markedly alters its path. Our structural and functional data suggest that the conserved Swi2/Snf2-family core ATPase domain promotes the forward movement of Pol II, and elucidate key roles for Rad26 in both TCR and transcription elongation

Compressed folder: Cianfrocco_Leschziner_Dryad_Upload

This folder contains the necessary data files to extract particles, classify 3D data, and determine a 4.6 Angstrom cryo-EM structure of the 80S yeast ribosome. For a step-by-step guide, please read more here: http://git.io/8LrCqg

Ollscoil na hAoise Seo.

Is trdthuil an uain f seo le breathnu ar roinnt forbairti atd tarlaithe cheana no atd d gcur i bhfeidhm faoi ldthair san oideachas triu leibhdal in £irinn. Duine ar bith atd ag teagasc in ollscoil no i bhforas eile oideachais da leitheid le deich n6 cuig bliana ddag anuas beidh se tugtha faoi deara aige no aici go bhfuil athruithe m6ra tagtha ar an eamdil sin frd chdile. Td na hathmithe seo le sonru, cuir i gcds, i Hon agus i gcaighdedn na mac Idinn atd ag tarraingt anois ar an ollscoil; sa chdras modulach seimeastrach atd curtha i bhfeidhm i mdran gach ollscoil; san athstruchturu o bhonn atd imithe ar roinnt de na forais Idinn; agus sna sdla air sin ar fad, sa mhdadu cdatach atd tagtha ar ualach an riarachdin. Nuair a chuirtear leo seo an rachmas atd sa Hr de bharr fheabhas na heacnamaiochta agus an rdabhldid theicneolalochta a bhfuil tioncbar aige ar gach gnd de shaol an Idinn gan trdcht ar an saol m6r i gcoitinne, nior thdgtha ar dhuine a cheapadh gur institiuid de chineal eile atd san ollscoil seachas mar a bhiodh

Structure and dynamics of the ASB9 CUL-RING E3 Ligase.

The Cullin 5 (CUL5) Ring E3 ligase uses adaptors Elongins B and C (ELOB/C) to bind different SOCS-box-containing substrate receptors, determining the substrate specificity of the ligase. The 18-member ankyrin and SOCS box (ASB) family is the largest substrate receptor family. Here we report cryo-EM data for the substrate, creatine kinase (CKB) bound to ASB9-ELOB/C, and for full-length CUL5 bound to the RING protein, RBX2, which binds various E2s. To date, no full structures are available either for a substrate-bound ASB nor for CUL5. Hydrogen-deuterium exchange (HDX-MS) mapped onto a full structural model of the ligase revealed long-range allostery extending from the substrate through CUL5. We propose a revised allosteric mechanism for how CUL-E3 ligases function. ASB9 and CUL5 behave as rigid rods, connected through a hinge provided by ELOB/C transmitting long-range allosteric crosstalk from the substrate through CUL5 to the RBX2 flexible linker

Structure and dynamics of the ASB9 CUL-RING E3 Ligase

Multi-subunit Cullin (CUL)-RING ligases (CRL) form the largest family of E3 ligases and are composed of a substrate receptor, a CUL, and a RING-box (RBX) protein. Here, the authors use cryo-EM and HDX-MS to characterise the ASB9 CUL-RING E3 ligase and present the structure of ASB9-ELOB/C bound to the substrate creatine kinase and the full-length CUL5 structure in complex with RBX2, and they propose a revised allosteric mechanism for CUL-E3 ligase function