Structure and function of YidC and homologous membrane proteins

• Applicant: Professorin Dr. Irmgard Sinning
• Subject Area: Biochemistry
• Term: from 2008 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 50070218

Integral membrane proteins play crucial roles in all cells and comprise about 20-30% of the proteome. They preferentially use the co-translational targeting and insertion machinery of the universally conserved signal recognition particle (SRP) in conjunction with the SecYEG translocation channel. However, membrane proteins that play important roles in respiration and energy transduction mechanisms in bacteria, mitochondria and chloroplasts are inserted and assembled by the YidC/Oxa1/Alb3 family of membrane insertases. The analysis of E. coli and mitochondrial members of the YidC/Oxa1/Alb3 family is advanced for their insertase function and common principles are emerging, wheras the characterization of the chloroplast members Alb3/Alb4 lags still far behind. So far only low resolution structures for ribosome-bound Oxa1 and YidC are available from cryo-electronmicroscopy. In the second funding period we will therefore continue our efforts towards high resolution structure determination of a member of the YidC/Oxa1/Alb3 family. We aim to improve existing crystals by a combination of protein engineering and additives to increase protein stability and crystal contacts. In an interdisciplinary approach functional interactions will be analysed with special emphasis on Alb3 and Alb4.

• DFG Programme: Research Units
• Subproject of: FOR 967: Functions and Mechanisms of Ribosomal Tunnel Exit Ligands (RTeLs)