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Publication Abstract from PubMed

Transcription factor (TF) IIIC recruits RNA polymerase (Pol) III to most of its target genes. Recognition of intragenic A- and B-box motifs in transfer RNA (tRNA) genes by TFIIIC modules tauA and tauB is the first critical step for tRNA synthesis but is mechanistically poorly understood. Here, we report cryo-electron microscopy structures of the six-subunit human TFIIIC complex unbound and bound to a tRNA gene. The tauB module recognizes the B-box via DNA shape and sequence readout through the assembly of multiple winged-helix domains. TFIIIC220 forms an integral part of both tauA and tauB connecting the two subcomplexes via a ~550-amino acid residue flexible linker. Our data provide a structural mechanism by which high-affinity B-box recognition anchors TFIIIC to promoter DNA and permits scanning for low-affinity A-boxes and TFIIIB for Pol III activation.

Structural insights into human TFIIIC promoter recognition.,Seifert-Davila W, Girbig M, Hauptmann L, Hoffmann T, Eustermann S, Muller CW Sci Adv. 2023 Jul 7;9(27):eadh2019. doi: 10.1126/sciadv.adh2019. Epub 2023 Jul 7. PMID:37418517^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.