NAR Molecular Biology Database Collection entry number 174
Perler, F.B.
New England Biolabs, 32 Tozer Rd., Beverly, MA 01915, USA

Database Description

Inteins are self-catalytic protein splicing elements that interrupt host proteins, called exteins. Extein ligation to form a native peptide bond between the extein segments AND the presence of conserved intein motifs differentiate intein-mediated protein splicing from other post-translational processing events. InBase, the intein Database and Registry, is a curated compilation of published and unpublished information about protein splicing. It provides background material in a separate section called Intein Basics that is suitable for classroom use both on-line and as files to download. However, InBase’s main focus is to provide detailed information about inteins in a layered format with general discussions and tables pointing to more specific data. Individual intein records contain detailed information about each intein, including comments on unusual properties, submitter contact information and a reference list for each intein. The criteria for intein identification are described, which help differentiate inteins from other types of homing endonuclease genes. An intein-specific BLAST server assists in identifying new inteins. Genome sequencing groups are encouraged to submit intein data and can confidentially request help in finding inteins. The bibliography includes annotations for reviews, application papers, related papers and recent papers. PubMed hot links allow the reader to retrieve abstracts from the National Library of Medicine. Intein data can be submitted confidentially or for immediate release using the on-line Submission Form or by email.

Recent Developments

Several new inteins have been identified this year, including more alleles of the naturally split DnaE intein. More examples of novel protein engineering applications that take advantage of the C-terminal alpha-thioester formed on target proteins purified from intein vectors, such as the commercially available IMPACT system (NEB), have been published. Enzyme inhibitors have been selected in vivo using intein generated cyclic peptide libraries. Several groups have devised genetic selection systems for studying intein function and looking for intein inhibitors.


am grateful to my coworkers at NEB, Ellen M. Lambrinos and Ching Lin for help in maintaining InBase, Janos Posfai and Tamas Vincze for developing and maintaining the InBase BLAST server, and to all the intein workers who have submitted their published and unpublished data, especially Shmuel Pietrokovski.


Perler, F.B. (2002) InBase, the Intein Database. Nucleic Acids Res., 30, 383-384.

Go to the abstract in the NAR 2002 Database Issue.
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