The BIF Domain in Plant bHLH Proteins Is an ACT-Like Domain

A hydrophobic residue stabilizes dimers of regulatory ACT-like domains in plant basic helix–loop–helix transcription factors

“…For this, we first retrieved the sequence of all 175 maize bHLH factors from GRASSIUS ( grassisus.org ) ( 43 ). Because of the low amino acid sequence conservation between ACT-like domains ( 13 , 14 ), we determined whether they harbored an ACT domain by predicting secondary structures using PSIPRED ( 44 ). We found that 44 of 175 bHLH factors had an ACT-like domain, a frequency similar to what was previously determined for Arabidopsis ( 13 ), and this domain is always located at the C-terminus, as is the case for R and GL3 ( Fig.…”

“…Other motifs appear to be specific to the plant kingdom and include the ACT-like domain, a fold first identified in the aspartate kinase, chorismate mutase, and TyrA enzymes (hence the name, ACT) ( 12 ) and later shown to be present in about a third of the plant bHLH TFs ( 13 ). Similar to the structurally related bHLH protein interaction and function domain ( 14 , 15 ), the ACT-like domain can mediate PPIs ( 13 , 16 ).…”

Exploring the genetics of lesion and nodal resistance in pea (Pisum sativum L.) to Sclerotinia sclerotiorum using genome‐wide association studies and RNA‐Seq

“…Five transcripts found by both GWAS and RNA‐Seq had higher DE after S. sclerotiorum inoculation (Figure ). While the ACT domain repeat‐containing proteins have diverse functions in plant physiologies (Feller, Yuan, & Grotewold, ), the β‐glucosidase might be involved in cell wall reinforcement or releasing damage associated molecular patterns (DAMP) (Duran‐Flires & Heil, ). Additionally, one of the transcripts identified for nodal resistance is a putative VQ motif‐containing protein, which had higher expression in response to S. sclerotiorum infection (Figure b).…”

Exploring the Genetics of Lesion and Nodal Resistance in Pea (Pisum sativumL.) toSclerotinia sclerotiorumUsing Genome-wide Association Studies and RNA-Seq

“…7). While the ACT domain repeat-containing proteins have diverse functions in plant physiologies (Feller, Yuan, & Grotewold, 2017), the β-glucosidase might be involved in cell wall reinforcement or releasing damage associated molecular patterns (DAMP) (Duran-Flires & Heil, 2016). Additionally, one of the transcripts identified for nodal resistance is a putative VQ motif-containing protein, which had higher expression in ‘Lifter’ than PI 240515 at 24 hpi (Fig.…”