The H-2Kk MHC peptide-binding groove anchors the backbone of an octameric antigenic peptide in an unprecedented mode.

نویسندگان

  • Christine Kellenberger
  • Alain Roussel
  • Bernard Malissen
چکیده

A wealth of data has accumulated on the structure of mouse MHC class I (MHCI) molecules encoded by the H-2(b) and H-2(d) haplotypes. In contrast, there is a dearth of structural data regarding H-2(k)-encoded molecules. Therefore, the structures of H-2K(k) complexed to an octameric peptide from influenza A virus (HA(259-266)) and to a nonameric peptide from SV40 (SV40(560-568)) have been determined by x-ray crystallography at 2.5 and 3.0 A resolutions, respectively. The structure of the H-2K(k)-HA(259-266) complex reveals that residues located on the floor of the peptide-binding groove contact directly the backbone of the octameric peptide and force it to lie deep within the H-2K(k) groove. This unprecedented mode of peptide binding occurs despite the presence of bulky residues in the middle of the floor of the H-2K(k) peptide-binding groove. As a result, the Calpha atoms of peptide residues P5 and P6 are more buried than the corresponding residues of H-2K(b)-bound octapeptides, making them even less accessible to TCR contact. When bound to H-2K(k), the backbone of the SV40(560-568) nonapeptide bulges out of the peptide-binding groove and adopts a conformation reminiscent of that observed for peptides bound to H-2L(d). This structural convergence occurs despite the totally different architectures of the H-2L(d) and H-2K(k) peptide-binding grooves. Therefore, these two H-2K(k)-peptide complexes provide insights into the mechanisms through which MHC polymorphism outside primary peptide pockets influences the conformation of the bound peptides and have implications for TCR recognition and vaccine design.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Simulation of Major Histocompatibility Complex (MHC) Structure and Peptide Loading into an MHC Binding Pocket with Teachers’Hands

Molecular understanding of three-dimensional (3D) peptide: MHC models require both basic knowledge of computational modeling and skilled visual perception, which are not possessed by all students. The present model aims to simulate MHC molecular structure with the hands and make a profound impression on the students.

متن کامل

Narrow groove and restricted anchors of MHC class I molecule BF2*0401 plus peptide transporter restriction can explain disease susceptibility of B4 chickens.

The MHC has genetic associations with many diseases, often due to differences in presentation of antigenic peptides by polymorphic MHC molecules to T lymphocytes of the immune system. In chickens, only a single classical class I molecule in each MHC haplotype is expressed well due to coevolution with the polymorphic TAPs which means that resistance and susceptibility to infectious pathogens are...

متن کامل

A hairpin turn in a class II MHC-bound peptide orients residues outside the binding groove for T cell recognition.

T cells generally recognize peptide antigens bound to MHC proteins through contacts with residues found within or immediately flanking the seven- to nine-residue sequence accommodated in the MHC peptide-binding groove. However, some T cells require peptide residues outside this region for activation, the structural basis for which is unknown. Here, we have investigated a HIV Gag-specific T cell...

متن کامل

Knowledge-based structure prediction of MHC class I bound peptides: a study of 23 complexes.

BACKGROUND The binding of T-cell antigenic peptides to MHC molecules is a prerequisite for their immunogenicity. The ability to identify binding peptides based on the protein sequence is of great importance to the rational design of peptide vaccines. As the requirements for peptide binding cannot be fully explained by the peptide sequence per se, structural considerations should be taken into a...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Journal of immunology

دوره 175 6  شماره 

صفحات  -

تاریخ انتشار 2005