PDBsum entry 5k6p

Contractile protein

PDB id: 5k6p

Contents

Protein chain

137 a.a.

PDB id:

5k6p

Name:

Contractile protein

Title:

The nmr structure of the m domain tri-helix bundle and c2 of human cardiac myosin binding protein c

Structure:

Myosin-binding protein c, cardiac-type. Chain: a. Fragment: residues 319-451. Synonym: cardiac mybp-c,c-protein,cardiac muscle isoform. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Tissue: heart. Gene: mybpc3. Expressed in: escherichia coli. Expression_system_taxid: 562.

NMR struc:

20 models

Authors:

K.A.Michie,A.H.Kwan,C.S.Tung,J.M.Guss,J.Trewhella

Key ref:

K.A.Michie et al. (2016). A Highly Conserved Yet Flexible Linker Is Part of a Polymorphic Protein-Binding Domain in Myosin-Binding Protein C. Structure, 24, 2000-2007. PubMed id: 27720588 DOI: 10.1016/j.str.2016.08.018

Date:

25-May-16 Release date: 09-Nov-16

Protein chain

Q14896  (MYPC3_HUMAN) -  Myosin-binding protein C, cardiac-type from Homo sapiens

Seq: 1274 a.a.

Struc: 137 a.a.*

* PDB and UniProt seqs differ at 3 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1016/j.str.2016.08.018

Structure 24:2000-2007 (2016)

PubMed id: 27720588

A Highly Conserved Yet Flexible Linker Is Part of a Polymorphic Protein-Binding Domain in Myosin-Binding Protein C.

K.A.Michie, A.H.Kwan, C.S.Tung, J.M.Guss, J.Trewhella.

ABSTRACT

The nuclear magnetic resonance (NMR) structure of the tri-helix bundle (THB) of the m-domain plus C2 (ΔmC2) of myosin-binding protein C (MyBP-C) has revealed a highly flexible seven-residue linker between the structured THB and C2. Bioinformatics shows significant patterns of conservation across the THB-linker sequence, with the linker containing a strictly conserved serine in all MyBP-C isoforms. Clinically linked mutations further support the functional significance of the THB-linker region. NMR, small-angle X-ray scattering, and binding studies show the THB-linker plus the first ten residues of C2 undergo dramatic changes when ΔmC2 binds Ca²⁺-calmodulin, with the linker and C2 N-terminal residues contributing significantly to the affinity. Modeling of all available experimental data indicates that the THB tertiary structure must be disrupted to form the complex. These results are discussed in the context of the THB-linker and the N-terminal residues of C2 forming a polymorphic binding domain that could accommodate multiple binding partners in the dynamic sarcomere.