Recombinant B. subtilis Penicillin-binding protein 3 (His tag)

Supplementary information

This supplementary information is collated from multiple sources and compiled automatically.

Penicillin-binding protein 3 (PBP3) also known as FtsI is an enzyme involved in bacterial cell wall synthesis. This protein plays a central role in the last stages of peptidoglycan synthesis catalyzing transpeptidation reactions that cross-link peptide chains. PBP3 weighs about 71 kDa and is expressed in the membrane of Gram-negative bacteria. By anchoring in the bacterial inner membrane it interacts with other proteins essential for bacterial growth and division.

Biological function summary

PBP3 is important in maintaining the integrity and shape of bacterial cells. It forms part of a larger complex known as the divisome which coordinates cell division. As a central player in septum formation PBP3 ensures proper cellular division by organizing the synthesis of new cell wall material at the division site. The disruption of PBP3 function can severely affect bacterial viability making it a significant target for antibiotics.

Pathways

The synthesis of peptidoglycan represents the central role for PBP3. It integrates into the biosynthesis and remodeling pathways of the bacterial cell wall. These pathways are vital for maintaining cell structure and survival. Additionally PBP3 interacts with other penicillin-binding proteins (PBPs) in the pathway coordinating the regulated activity necessary for cell wall expansion and septation. This process is tightly linked with proteins such as FtsZ which positions the divisome complex during cell division.

The altered activity of PBP3 contributes significantly to antibiotic resistance. Bacteria modify PBP3 to decrease its affinity for beta-lactam antibiotics reducing these drugs' efficacy. This resistance mechanism plays an important role in conditions like penicillin-resistant Neisseria gonorrhoeae and methicillin-resistant Staphylococcus aureus (MRSA). Both of these bacteria utilize altered PBPs including PBP2a in MRSA to evade the bactericidal effects of beta-lactams highlighting the importance of PBP3 in the development and spread of antibiotic resistance.