Home  |  Contact
PROSITE documentation PDOC00659

D-alanine--D-alanine ligase signatures


D-alanine--D-alanine ligase (EC is a bacterial enzyme involved in cell-wall biosynthesis. It participates in forming UDP-N-acetylmuramyl pentapeptide, the peptidoglycan precursor.

In Escherichia coli and related bacteria, there are two different D-ala--D-ala ligase isozymes (genes ddlA and ddlB) [1]. In Enterobacterium faecium and gallinarum, genes vanA and vanC encode D-ala--D-ala ligases of altered specificity, which catalyze ester bond formations between D-ala and various D-hydroxy acids [2]. They are required for resistance to glycopeptide antibiotics, such as vancomycin which inhibits late stages in cell-wall synthesis.

These enzymes are proteins of 300 to 360 amino acids. There are many conserved regions, of which we selected two as signature patterns. The first pattern, which is Gly-rich and could be involved in ATP-binding, is located near the N-terminal extremity, the second is in the C-terminal section.

Last update:

December 2004 / Patterns and text revised.

Technical section

PROSITE methods (with tools and information) covered by this documentation:

DALA_DALA_LIGASE_1, PS00843; D-alanine--D-alanine ligase signature 1  (PATTERN)

DALA_DALA_LIGASE_2, PS00844; D-alanine--D-alanine ligase signature 2  (PATTERN)


1AuthorsZawadzke L.E. Bugg T.D. Walsh C.T.
TitleExistence of two D-alanine:D-alanine ligases in Escherichia coli: cloning and sequencing of the ddlA gene and purification and characterization of the DdlA and DdlB enzymes.
SourceBiochemistry 30:1673-1682(1991).
PubMed ID1993184

2AuthorsDutka-Malen S. Molinas C. Arthur M. Courvalin P.
SourceGene 112:53-58(1992).

PROSITE is copyright. It is produced by the SIB Swiss Institute Bioinformatics. There are no restrictions on its use by non-profit institutions as long as its content is in no way modified. Usage by and for commercial entities requires a license agreement. For information about the licensing scheme send an email to
Prosite License or see: prosite_license.html.


View entry in original PROSITE document format
View entry in raw text format (no links)