PDBsum entry 6t32

Biotin-binding protein

PDB id: 6t32

Contents

Protein chains

121 a.a.

Ligands

HL9 ×2

Waters ×197

PDB id:

6t32

Name:

Biotin-binding protein

Title:

Streptavidin variants harbouring an artificial organocatalyst based cofactor

Structure:

Streptavidin. Chain: a, b. Engineered: yes

Source:

Streptomyces avidinii. Organism_taxid: 1895. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

1.75Å R-factor: 0.163 R-free: 0.191

Authors:

H.Lechner,B.Hocker

Key ref:

H.Lechner et al. (2021). An Artificial Cofactor Catalyzing the Baylis-Hillman Reaction with Designed Streptavidin as Protein Host*. Chembiochem, 22, 1573-1577. PubMed id: 33400831 DOI: 10.1002/cbic.202000880

Date:

10-Oct-19 Release date: 18-Nov-20

Protein chains

P22629  (SAV_STRAV) -  Streptavidin from Streptomyces avidinii

Seq: 183 a.a.

Struc: 121 a.a.*

* PDB and UniProt seqs differ at 7 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1002/cbic.202000880

Chembiochem 22:1573-1577 (2021)

PubMed id: 33400831

An Artificial Cofactor Catalyzing the Baylis-Hillman Reaction with Designed Streptavidin as Protein Host*.

H.Lechner, V.R.Emann, M.Breuning, B.Höcker.

ABSTRACT

An artificial cofactor based on an organocatalyst embedded in a protein has been used to conduct the Baylis-Hillman reaction in a buffered system. As protein host, we chose streptavidin, as it can be easily crystallized and thereby supports the design process. The protein host around the cofactor was rationally designed on the basis of high-resolution crystal structures obtained after each variation of the amino acid sequence. Additionally, DFT-calculated intermediates and transition states were used to rationalize the observed activity. Finally, repeated cycles of structure determination and redesign led to a system with an up to one order of magnitude increase in activity over the bare cofactor and to the most active proteinogenic catalyst for the Baylis-Hillman reaction known today.