King Jessica, Gisselbrecht Stephen S, Dias Julie-Alexia, Jeong Raehoon, Rothman Elisabeth, Bulyk Martha L
Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, USA.
Computational Biology and Quantitative Genetics Program, Harvard T.H. Chan School of Public Health Boston, MA, USA.
bioRxiv. 2025 May 30:2025.05.27.656303. doi: 10.1101/2025.05.27.656303.
Recognition of specific DNA sequences by transcription factors (TFs) is a key step in transcriptional control of gene expression. While most forkhead (FH) TFs bind either an FKH (RYAAAYA) or an FHL (GACGC) recognition motif, some FHs can bind both motifs. Mechanisms that control whether a FH is monospecific versus bispecific have remained unknown. Screening a library of 12 reference FH proteins, 61 naturally occurring missense variants including clinical variants, and 22 designed mutant FHs for DNA binding activity using universal ("all 10-mer") protein binding microarrays (PBMs) revealed non-DNA-contacting residues that control mono- versus bispecificity. Variation in non-DNA-contacting amino acid residues of TFs is associated with human traits and may play a role in the evolution of TF DNA binding activities and gene regulatory networks.
转录因子（TFs）对特定DNA序列的识别是基因表达转录调控中的关键步骤。虽然大多数叉头（FH）转录因子结合FKH（RYAAAYA）或FHL（GACGC）识别基序，但有些FH转录因子可以同时结合这两种基序。控制FH转录因子是单特异性还是双特异性的机制尚不清楚。使用通用（“所有10聚体”）蛋白质结合微阵列（PBMs）筛选12种参考FH蛋白质文库、61种包括临床变体在内的天然错义变体以及22种设计的突变FH转录因子的DNA结合活性，发现了控制单特异性与双特异性的非DNA接触残基。转录因子非DNA接触氨基酸残基的变异与人类性状相关，可能在转录因子DNA结合活性和基因调控网络的进化中发挥作用。
