The Asparaginase Database is a
resource for asparaginase sequences, structures, and biochemical
annotations organized by a phylogenetically driven classification.
i
"Biochemical characterization revealed that ASNaseGt existed
in an oligomeric form in solution which can be converted to
the most active tetrameric form by the addition of thiol
reducers."
L-Asparaginases are a diverse group of enzymes that catalyse the
hydrolysis of L-asparagine. In medicine, they play a pivotal role in the
treatment of acute lymphoblastic leukaemia and lymphoblastic lymphoma,
while in the food industry, they are used to reduce neurotoxic
acrylamide levels in processed products.
About the Database
The Asparaginase Database is a resource that provides organized
L-asparaginase sequences and structures within their phylogenetic
families along with biochemical annotations for characterized enzymes.
The database is built on a comprehensive phylogenetically driven
L-asparaginase classification that integrates existing biochemical
knowledge with expanding sequence data. This system is not only free of
historical ambiguities but could also aid scientists with understanding
and discovering L-asparaginases with improved functional or structural
properties.
The Classification
The L-asparaginase classification that underpins this database is based
on extensive sequence (and structural) analysis of all known and
predicted L-asparaginases. As these enzymes form a complex and
intertwined group, sequence similarity analysis was selected as the best
primary driver of the classification, rather than other factors like
taxonomy, cellular location or enzyme kinetics, enabling a more
objective and natural classification less biased by the order of
scientific discovery. This bioinformatics-centred approach also makes
the classification more robust to future discoveries.
Asparaginase Classes
There are three fundamental classes of L-asparaginases, each with unique
conserved motifs and structures. No homology could be inferred between
these classes of L-asparaginases, as they show very low mutual sequence
identity. Sequences are categorized into Class 1 (historically
bacterial-type), Class 2 (plant type) and Class 3 (R. etli-type)
L-asparaginases. Sequences in these classes were clustered and aligned
independently. This allowed further division into new phylogenetic
families and clans inferred from a comprehensive phylogenetic analysis.
Conserved Motifs
For each class and family conserved sequence motifs are presented. Some
motives are universal in the class, others are specific to related
families. They were determined from an alignment of a selection of many
representative sequences that generally have mutual sequence
similarities of less than 80%. The random selection was refined by
removing the most obvious outliers and adding a selected reference
sequence. The resulting motifs are given with consensus percentages for
the representative sequences and are mapped on to a selected sequence.
These percentages indicate a trend in the family and do not reflect
every single sequence in the family, as each family has a large number
of sequences. Generally only motifs present in several families are
described.
Disclaimer
This database is a work in progress and not all functionalities are
fully available yet. Information provided on families and classes of
L-asparaginases is general and might not apply to every sequence or
protein. Although many, not all experimentally studied L-asparaginases
could be presented. Please check information that is provided on
proteins in the original publication/source.
The Asparaginase Database | Release 2025-01 | Contact:
