Coiled-coil structure of group A streptococcal M proteins. Different temperature stability of class A and C proteins by hydrophobic-nonhydrophobic amino acid substitutions at heptad positions a and d
(1997) In Biochemistry 36(16). p.4987-4994- Abstract
M proteins and M-like proteins, expressed on the surface of group A streptococci and binding to human plasma proteins, can be divided into two classes, A and C, depending on the structure of the central repeated regions. The class C proteins have been shown to be dimers with a coiled-coil structure. In this work, we have compared the structure and binding of a class A protein, Mrp4, and a class C protein, Arp4, expressed by the same bacterial strain. Circular dichroism spectra, gel filtration, and binding assays showed that both proteins had a coiled-coil dimer configuration and a high-affinity binding at 20 degrees C. However, striking differences were seen at 37 degrees C. The class A protein, Mrp4, was still a coiled-coil dimer with... (More)
M proteins and M-like proteins, expressed on the surface of group A streptococci and binding to human plasma proteins, can be divided into two classes, A and C, depending on the structure of the central repeated regions. The class C proteins have been shown to be dimers with a coiled-coil structure. In this work, we have compared the structure and binding of a class A protein, Mrp4, and a class C protein, Arp4, expressed by the same bacterial strain. Circular dichroism spectra, gel filtration, and binding assays showed that both proteins had a coiled-coil dimer configuration and a high-affinity binding at 20 degrees C. However, striking differences were seen at 37 degrees C. The class A protein, Mrp4, was still a coiled-coil dimer with high affinity binding activity, whereas the class C protein, Arp4, had lost both the coiled-coil structure and binding activity. Raising the temperature even higher, Mrp4 retained the coiled-coil structure up to 70-90 degrees C. Furthermore, a recombinant protein, Mrp(C), in which the A-repeats of Mrp4 were replaced by the C-repeats of Arp4, lost its coiled-coil structure and fibrinogen-binding around 40-45 degrees C. These results suggest a high thermal stability of class A proteins and a low stability of class C proteins and that the structural basis for this can be found partly in the A- and C-repeats. Analysis of the amino acid sequences of the A- and C-repeats, revealed a large difference, 87% and 45%, respectively, in the content of hydrophobic amino acid residues in the positions regarded as important for the formation of the coiled-coil structure. In particular, several alanine residues in the A-repeats were replaced by serine residues in the C-repeats. Our results suggest that important structural and functional changes within the M protein family have evolved by specific hydrophobic-nonhydrophobic amino acid replacements.
(Less)
- author
- Cedervall, T LU ; Johansson, M U LU and Akerström, B LU
- organization
- publishing date
- 1997-04-22
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Amino Acid Sequence, Amino Acids/analysis, Antigens, Bacterial/chemistry, Antigens, Surface/chemistry, Bacterial Outer Membrane Proteins, Bacterial Proteins/chemistry, Carrier Proteins/chemistry, Chromatography, Gel, Circular Dichroism, Fibrinogen/metabolism, Hot Temperature, Humans, Molecular Sequence Data, Mutagenesis, Site-Directed, Protein Conformation, Protein Structure, Secondary, Recombinant Proteins/metabolism, Streptococcus pyogenes/chemistry, Structure-Activity Relationship
- in
- Biochemistry
- volume
- 36
- issue
- 16
- pages
- 4987 - 4994
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- pmid:9125521
- scopus:0030887662
- ISSN
- 0006-2960
- DOI
- 10.1021/bi962971q
- language
- English
- LU publication?
- yes
- id
- ba53f522-1fc5-490c-af2f-df165ba3f46b
- date added to LUP
- 2019-05-22 10:18:07
- date last changed
- 2024-03-03 09:57:26
@article{ba53f522-1fc5-490c-af2f-df165ba3f46b,
abstract = {{<p>M proteins and M-like proteins, expressed on the surface of group A streptococci and binding to human plasma proteins, can be divided into two classes, A and C, depending on the structure of the central repeated regions. The class C proteins have been shown to be dimers with a coiled-coil structure. In this work, we have compared the structure and binding of a class A protein, Mrp4, and a class C protein, Arp4, expressed by the same bacterial strain. Circular dichroism spectra, gel filtration, and binding assays showed that both proteins had a coiled-coil dimer configuration and a high-affinity binding at 20 degrees C. However, striking differences were seen at 37 degrees C. The class A protein, Mrp4, was still a coiled-coil dimer with high affinity binding activity, whereas the class C protein, Arp4, had lost both the coiled-coil structure and binding activity. Raising the temperature even higher, Mrp4 retained the coiled-coil structure up to 70-90 degrees C. Furthermore, a recombinant protein, Mrp(C), in which the A-repeats of Mrp4 were replaced by the C-repeats of Arp4, lost its coiled-coil structure and fibrinogen-binding around 40-45 degrees C. These results suggest a high thermal stability of class A proteins and a low stability of class C proteins and that the structural basis for this can be found partly in the A- and C-repeats. Analysis of the amino acid sequences of the A- and C-repeats, revealed a large difference, 87% and 45%, respectively, in the content of hydrophobic amino acid residues in the positions regarded as important for the formation of the coiled-coil structure. In particular, several alanine residues in the A-repeats were replaced by serine residues in the C-repeats. Our results suggest that important structural and functional changes within the M protein family have evolved by specific hydrophobic-nonhydrophobic amino acid replacements.</p>}},
author = {{Cedervall, T and Johansson, M U and Akerström, B}},
issn = {{0006-2960}},
keywords = {{Amino Acid Sequence; Amino Acids/analysis; Antigens, Bacterial/chemistry; Antigens, Surface/chemistry; Bacterial Outer Membrane Proteins; Bacterial Proteins/chemistry; Carrier Proteins/chemistry; Chromatography, Gel; Circular Dichroism; Fibrinogen/metabolism; Hot Temperature; Humans; Molecular Sequence Data; Mutagenesis, Site-Directed; Protein Conformation; Protein Structure, Secondary; Recombinant Proteins/metabolism; Streptococcus pyogenes/chemistry; Structure-Activity Relationship}},
language = {{eng}},
month = {{04}},
number = {{16}},
pages = {{4987--4994}},
publisher = {{The American Chemical Society (ACS)}},
series = {{Biochemistry}},
title = {{Coiled-coil structure of group A streptococcal M proteins. Different temperature stability of class A and C proteins by hydrophobic-nonhydrophobic amino acid substitutions at heptad positions a and d}},
url = {{http://dx.doi.org/10.1021/bi962971q}},
doi = {{10.1021/bi962971q}},
volume = {{36}},
year = {{1997}},
}