REBASE

REBASE: Database of Restriction-Modification Systems

REBASE curates and annotates data on restriction enzymes, DNA methyltransferases, homing endonucleases, and related proteins involved in restriction-modification (R-M) systems, including sequence, structural, and genomic context information.

Key Features:

• Recognition and Cleavage Sites: Provides experimentally determined recognition sequences and DNA cleavage positions for restriction enzymes.
• Isoschizomers and Neoschizomers: Classifies enzymes with identical recognition sequences (isoschizomers) and those recognizing similar but distinct sequences (neoschizomers).
• Methylation Sensitivity: Annotates restriction enzyme sensitivity to specific DNA methylation patterns.
• Crystal and Sequence Data: Integrates protein sequence data and crystallographic structures to support functional and evolutionary analyses.
• Homing Endonucleases: Includes experimentally characterized homing endonucleases associated with mobile genetic elements.
• Putative R-M Systems: Catalogs predicted restriction-modification systems identified in sequence databases.
• Genomic Descriptions: Summarizes R-M system content across fully sequenced genomes with annotated system components.

Scientific Applications:

• Molecular Cloning and Genome Engineering: Supports enzyme selection, comparative analysis of restriction enzymes, and characterization of DNA methyltransferases and R-M systems in genomic studies.
• Evolutionary and Structural Biology: Enables analysis of sequence variation, structural mechanisms, and evolutionary relationships among restriction enzymes and associated proteins.

Methodology:

Data are manually curated from experimental literature and sequence databases, integrating recognition sequences, cleavage sites, methylation sensitivity profiles, protein sequences, crystallographic structures, and genome annotations to systematically classify and describe restriction-modification systems.