Summary information and primary citation
- PDB-id
-
4rtm;
DSSR-derived features in text and
JSON formats
- Class
- transferase-DNA
- Method
- X-ray (2.5 Å)
- Summary
- Complex of escherichia coli DNA adenine
methyltransferase (dam) with adomet and with DNA containing
distal pap regulon sequence
- Reference
-
Horton JR, Zhang X, Blumenthal RM, Cheng X (2015):
"Structures
of Escherichia coli DNA adenine methyltransferase (Dam)
in complex with a non-GATC sequence: potential
implications for methylation-independent transcriptional
repression." Nucleic Acids Res.,
43, 4296-4308. doi: 10.1093/nar/gkv251.
- Abstract
- DNA adenine methyltransferase (Dam) is widespread and
conserved among the γ-proteobacteria. Methylation of the
Ade in GATC sequences regulates diverse bacterial cell
functions, including gene expression, mismatch repair and
chromosome replication. Dam also controls virulence in many
pathogenic Gram-negative bacteria. An unexplained and
perplexing observation about Escherichia coli Dam (EcoDam)
is that there is no obvious relationship between the genes
that are transcriptionally responsive to Dam and the
promoter-proximal presence of GATC sequences. Here, we
demonstrate that EcoDam interacts with a 5-base pair
non-cognate sequence distinct from GATC. The crystal
structure of a non-cognate complex allowed us to identify a
DNA binding element, GTYTA/TARAC (where Y = C/T and R =
A/G). This element immediately flanks GATC sites in some
Dam-regulated promoters, including the Pap operon which
specifies pyelonephritis-associated pili. In addition, Dam
interacts with near-cognate GATC sequences (i.e. 3/4-site
ATC and GAT). Taken together, these results imply that Dam,
in addition to being responsible for GATC methylation,
could also function as a methylation-independent
transcriptional repressor.
