Lesion recognition by XPC, TFIIH and XPA in DNA excision repair.

Nucleotide excision repair removes DNA lesions caused by ultraviolet light, cisplatin-like compounds and bulky adducts. After initial recognition by XPC in global genome repair or a stalled RNA polymerase in transcription-coupled repair, damaged DNA is transferred to the seven-subunit TFIIH core complex (Core7) for verification and dual incisions by the XPF and XPG nucleases. Structures capturing lesion recognition by the yeast XPC homologue Rad4 and TFIIH in transcription initiation or DNA repair have been separately reported.

An engineered IL-2 partial agonist promotes CD8 T cell stemness.

Adoptive transfer of antigen-specific T cells represents a major advance in cancer immunotherapy, with robust clinical outcomes in some patients. Both the number of transferred T cells and their differentiation state are critical determinants of effective responses. T cells can be expanded with T cell receptor (TCR)-mediated stimulation and interleukin-2, but this can lead to differentiation into effector T cells and lower therapeutic efficacy, whereas maintenance of a more stem-cell-like state before adoptive transfer is beneficial.

gP2S, an Information Management System for CryoEM Experiments.

Cryogenic electron microscopy (cryoEM) has become an integral part of many drug-discovery projects because crystallography of the protein target is not always achievable and cryoEM provides an alternative means to support structure-based ligand design. When dealing with a large number of distinct projects, and within each project a potentially large number of ligand-protein co-structures, accurate record keeping rapidly becomes challenging. Many experimental parameters are tuned for each target, including at the sample preparation, grid preparation, and microscopy stages.

Tripartite DNA Lesion Recognition and Verification by XPC, TFIIH, and XPA in Nucleotide Excision Repair.

Transcription factor IIH (TFIIH) is essential for both transcription and nucleotide excision repair (NER). DNA lesions are initially detected by NER factors XPC and XPE or stalled RNA polymerases, but only bulky lesions are preferentially repaired by NER. To elucidate substrate specificity in NER, we have prepared homogeneous human ten-subunit TFIIH and its seven-subunit core (Core7) without the CAK module and show that bulky lesions in DNA inhibit the ATPase and helicase activities of both XPB and XPD in Core7 to promote NER, whereas non-genuine NER substrates have no such effect.

An investigation of the affinities, specificity and kinetics involved in the interaction between the Yin Yang 1 transcription factor and DNA.

Human transcription factor Yin Yang 1 (YY1) is a four zinc-finger protein that regulates a large number of genes with various biological functions in processes such as development, carcinogenesis and B-cell maturation. The natural binding sites of YY1 are relatively unconserved and have a short core sequence (CCAT). We were interested in determining how YY1 recognizes its binding sites and achieves the necessary sequence selectivity in the cell.

Efficient overexpression and purification of active full-length human transcription factor Yin Yang 1 in Escherichia coli.

The Yin Yang 1 protein is a zinc finger transcription factor involved in the regulation of diverse cellular processes through DNA and protein-protein interactions. Here we present an improved method for the expression and purification of the human full-length YY1 protein from Escherichia coli. The protein was first purified using denaturing conditions, refolded using optimized conditions and then purified using a DNA-affinity column to ≥ 95% purity; this process provided a high final yield and highly active protein.