Structure, specificity, and mode of interaction for bacterial albumin-binding modules.

• We have determined the solution structure of an albumin binding domain of protein G, a surface protein of group C and G streptococci. We find that it folds into a left handed three-helix bundle similar to the albumin binding domain of protein PAB from Peptostreptococcus magnus. The two domains share 59% sequence identity, are thermally very stable, and bind to the same site on human serum albumin. The albumin binding site, the first determined for this structural motif known as the GA module, comprises residues spanning the first loop to the beginning of the third helix and includes the most conserved region of GA modules. The two GA modules have different affinities for albumin from different species, and their albumin binding patterns correspond directly to the host specificity of C/G streptococci and P. magnus, respectively. These studies of the evolution, structure, and binding properties of the GA module emphasize the power of bacterial adaptation and underline ecological and medical problems connected with the use of antibiotics.

Subject headings

NATURVETENSKAP  -- Kemi -- Fysikalisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Physical Chemistry (hsv//eng)

Keyword

Binding Competitive

Circular Dichroism

Dose-Response Relationship Drug

Drug Resistance

Evolution Molecular

Inhibitory Concentration 50

Kinetics

Magnetic Resonance Spectroscopy

Models Molecular

Molecular Sequence Data

Peptostreptococcus : metabolism

Protein Binding

Sequence Homology Amino Acid

Rabbits

Binding Sites

Amino Acid Sequence

Animal

Serum Albumin : chemistry : metabolism

Substrate Specificity

Support Non-U.S. Gov't

Temperature

streptococcal protein-g

Publication and Content Type

art (subject category)

ref (subject category)