The PASTA domain is a small
protein domain
In molecular biology, a protein domain is a region of a protein's polypeptide chain that is self-stabilizing and that folds independently from the rest. Each domain forms a compact folded three-dimensional structure. Many proteins consist o ...
that can bind to the
beta-lactam
A beta-lactam (β-lactam) ring is a four-membered lactam. A ''lactam'' is a cyclic amide, and ''beta''-lactams are named so because the nitrogen atom is attached to the β-carbon atom relative to the carbonyl. The simplest β-lactam possible i ...
ring portion of various
β-lactam antibiotic
β-lactam antibiotics (beta-lactam antibiotics) are antibiotics that contain a beta-lactam ring in their chemical
structure. This includes penicillin derivatives ( penams), cephalosporins and cephamycins ( cephems), monobactams, carbapenems and ...
s.
The domain was initially discovered in 2002 by Yeats and colleagues as a region of sequence similarity found in
penicillin binding proteins
Penicillin-binding proteins (PBPs) are a group of proteins that are characterized by their affinity for and binding of penicillin. They are a normal constituent of many bacteria; the name just reflects the way by which the protein was discov ...
and PknB-like kinases found in some bacteria. The name is an acronym derived from PBP and Serine/Threonine kinase Associated domain.
Structure
The PASTA domain adopts a structure composed of an
alpha-helix
The alpha helix (α-helix) is a common motif in the secondary structure of proteins and is a right hand- helix conformation in which every backbone N−H group hydrogen bonds to the backbone C=O group of the amino acid located four residues ear ...
followed by three
beta strand
The beta sheet, (β-sheet) (also β-pleated sheet) is a common motif of the regular protein secondary structure. Beta sheets consist of beta strands (β-strands) connected laterally by at least two or three backbone hydrogen bonds, forming a gen ...
s. Recent structural studies show that the extracellular region of PknB that is composed of four PASTA domains shows a linear arrangement of the domains.
Species distribution
PASTA domains are found in a variety of bacterial species including gram-positive
Bacillota
The Bacillota (synonym Firmicutes) are a phylum of bacteria, most of which have gram-positive cell wall structure. The renaming of phyla such as Firmicutes in 2021 remains controversial among microbiologists, many of whom continue to use the ea ...
and
Actinomycetota
The ''Actinomycetota'' (or ''Actinobacteria'') are a phylum of all gram-positive bacteria. They can be terrestrial or aquatic. They are of great economic importance to humans because agriculture and forests depend on their contributions to soi ...
.
References
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Protein domains