PDBsum entry 5f3x

Structural protein/protein binding

PDB id: 5f3x

Contents

Protein chains

189 a.a.

75 a.a.

Metals

_CL ×2

Waters ×19

PDB id:

5f3x

Name:

Structural protein/protein binding

Title:

Crystal structure of harmonin npdz1 in complex with anks4b sam-pbm

Structure:

Harmonin. Chain: a, c. Fragment: npdz1, unp residues 1-194. Engineered: yes. Ankyrin repeat and sam domain-containing protein 4b. Chain: b, d. Fragment: sam-pbm, unp residues 345-423. Synonym: anks4b. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Gene: ush1c, aie75. Expressed in: escherichia coli. Expression_system_taxid: 562. Mus musculus. Mouse. Organism_taxid: 10090.

Resolution:

2.65Å R-factor: 0.229 R-free: 0.264

Authors:

J.Li,Y.He,Q.Lu,M.Zhang

Key ref:

J.Li et al. (2016). Mechanistic Basis of Organization of the Harmonin/USH1C-Mediated Brush Border Microvilli Tip-Link Complex. Dev Cell, 36, 179-189. PubMed id: 26812017 DOI: 10.1016/j.devcel.2015.12.020

Date:

03-Dec-15 Release date: 16-Mar-16

Protein chains

Q9Y6N9  (USH1C_HUMAN) -  Harmonin from Homo sapiens

Seq: 552 a.a.

Struc: 189 a.a.

Protein chains

Q8K3X6  (ANS4B_MOUSE) -  Ankyrin repeat and SAM domain-containing protein 4B from Mus musculus

Seq: 423 a.a.

Struc: 75 a.a.

DOI no: 10.1016/j.devcel.2015.12.020

Dev Cell 36:179-189 (2016)

PubMed id: 26812017

Mechanistic Basis of Organization of the Harmonin/USH1C-Mediated Brush Border Microvilli Tip-Link Complex.

J.Li, Y.He, Q.Lu, M.Zhang.

ABSTRACT

Brush border microvilli are actin-based protrusions lining the apical surface of epithelial cells in intestines and proximal tubules of kidneys. While brush border microvilli resemble the relatively well-characterized stereocilia of hair cells, the mechanistic basis of tip-link complex organization in microvilli is poorly understood. Here, we have biochemically and structurally characterized the following pairs of interactions: protocadherin 24 and Harmonin (also known as USH1C or AIE-75), Harmonin and myosin VIIb (MYO7B), Harmonin and ANKS4B, and ANKS4B and MYO7B. We show that Harmonin, ANKS4B, and MYO7B form a stable ternary complex for anchoring microvilli tip-link cadherins. Despite having only Harmonin in common, the microvilli and the stereocilia tip-link complexes are formed via strikingly similar interaction modes. These results not only provide insight into the mechanistic bases of brush border microvilli formation and maintenance but may also be valuable for understanding some gut and/or kidney diseases caused by perturbations of brush border microvilli structures.