Using structural-based protein engineering to modulate the differential inhibition effects of SAUGI on human and HSV uracil DNA glycosylase.

Uracil-DNA glycosylases (UDGs) are highly conserved proteins that can be found in a wide range of organisms, and are involved in the DNA repair and host defense systems. UDG activity is controlled by various cellular factors, including the uracil-DNA glycosylase inhibitors, which are DNA mimic proteins that prevent the DNA binding sites of UDGs from interacting with their DNA substrate. To date, only three uracil-DNA glycosylase inhibitors, phage UGI, p56, and Staphylococcus aureus SAUGI, have been determined.

The T4 phage DNA mimic protein Arn inhibits the DNA binding activity of the bacterial histone-like protein H-NS.

The T4 phage protein Arn (Anti restriction nuclease) was identified as an inhibitor of the restriction enzyme McrBC. However, until now its molecular mechanism remained unclear. In the present study we used structural approaches to investigate biological properties of Arn.

DNA mimic proteins: functions, structures, and bioinformatic analysis.

DNA mimic proteins have DNA-like negative surface charge distributions, and they function by occupying the DNA binding sites of DNA binding proteins to prevent these sites from being accessed by DNA. DNA mimic proteins control the activities of a variety of DNA binding proteins and are involved in a wide range of cellular mechanisms such as chromatin assembly, DNA repair, transcription regulation, and gene recombination. However, the sequences and structures of DNA mimic proteins are diverse, making them difficult to predict by bioinformatic search.

TcaR-ssDNA complex crystal structure reveals new DNA binding mechanism of the MarR family proteins.

The teicoplanin-associated locus regulator (TcaR) regulates gene expression of proteins on the intercellular adhesion (ica) locus involved in staphylococci poly-N-acetylglucosamine biosynthesis. The absence of TcaR increases poly-N-acetylglucosamine production and promotes biofilm formation. Until recently, the mechanism of multiple antibiotic resistance regulator family protein members, such as TcaR, was restricted to binding double-stranded DNA.

White spot syndrome virus protein ICP11: A histone-binding DNA mimic that disrupts nucleosome assembly.

White spot syndrome virus (WSSV) is a large ( approximately 300 kbp), double-stranded DNA eukaryotic virus that has caused serious disease in crustaceans worldwide. ICP11 is the most highly expressed WSSV nonstructural gene/protein, which strongly suggests its importance in WSSV infection; but until now, its function has remained obscure. We show here that ICP11 acts as a DNA mimic.