Poster abstracts

Poster number 21 submitted by Ryan Hard

Screening of One-Bead-One-Compound Peptide Libraries for the Sequence Specificity of PDZ, BUZ, and BRCT Domains

Ryan L. Hard (The Ohio State University), Dr. Ernesto J. Fuentes (The University of Iowa), Dr. Pei Zhou (Duke University), Dr. Junjie Chen (The University of Texas)

Abstract:

Postsynaptic Density-95/Discs Large/Zona Occluden-1 (PDZ) domains bind to the free C-termini of target proteins to mediate protein interactions and display either unique or overlapping binding specificities. The BUZ (binder of ubiquitin zinc-finger) domain binds to the free C-terminus of ubiquitin and therefore helps mediate ubiquitin-based signaling events. Tandem BRCA1 C-terminal (BRCT) domains interact with a variety of proteins involved in the DNA damage response and have been shown to associate with internal or C-terminal sequences of proteins in a phosphorylation-dependent manner.

The one-bead-one-compound (OBOC) combinatorial library approach allows for the determination of individual binding sequences to proteins of interest, which can be compiled and analyzed to determine the binding specificity of a particular protein domain. A C-terminal OBOC peptide library was used to define the sequence specificity of the PDZ domains of Tiam-1 and Tiam-2 and the BUZ domains of Ubp-M and HDAC6. A modified C-terminal OBOC peptide library containing a fixed phosphoserine/phosphothreonine, along with an OBOC peptide library containing free-floating phosphoserine/phosphothreonine residues, was used to determine the sequence specificity of all known human tandem BRCT domains.

References:
1.Shepherd, TR, Hard, Ryan, Murray, Ann M., Pei, Dehua, and Fuentes, Ernesto J. (2011) Distinct Ligand Specificity of the Tiam1 and Tiam2 PDZ Domains. Biochemistry 50 (8), pp. 1296-1308.
2. Hard, RL, Liu, J, Shen, J, Zhou P, and Pei, D. (2010) HDAC6 and Ubp-M BUZ Domains Recognize Specific C-Terminal Sequences of Proteins. Biochemistry 49 (50), pp. 10737-46.

Keywords: Peptide Library