Identification of pneumococcal proteins that are functionally linked to penicillin-binding protein 2b (PBP2b).
The oval shape of pneumococci results from a combination of septal and lateral peptidoglycan synthesis. The septal cross-wall is synthesized by the divisome, while the elongasome drives cell elongation by inserting new peptidoglycan into the lateral cell wall. Each of these molecular machines contains penicillin-binding proteins (PBPs), which catalyze the final stages of peptidoglycan synthesis, plus a number of accessory proteins. Much effort has been made to identify these accessory proteins and determine their function. In the present paper we have used a novel approach to identify members of the pneumococcal elongasome that are functionally closely linked to PBP2b. We discovered that cells depleted in PBP2b, a key component of the elongasome, display several distinct phenotypic traits. We searched for proteins that, when depleted or deleted, display the same phenotypic changes. Four proteins, RodA, MreD, DivIVA and Spr0777, were identified by this approach. Together with PBP2b these proteins are essential for the normal function of the elongasome. Furthermore, our findings suggest that DivIVA, which was previously assigned as a divisomal protein, is required to correctly localize the elongasome at the negatively curved membrane region between the septal and lateral cell wall.
Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, NO-1432, Norway.
Daniel
D
Straume
Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, NO-1432, Norway.
Gro Anita
GA
Stamsås
Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, NO-1432, Norway.
Kari Helene
KH
Berg
Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, NO-1432, Norway.
Zhian
Z
Salehian
Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, NO-1432, Norway.
Leiv Sigve
LS
Håvarstein
D000595:Amino Acid Sequence; D019881:Aminoacyltransferases / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000378:metabolism*; D049108:Cell Enlargement; D002473:Cell Wall / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D046915:Penicillin-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D010406:Penicillins; D010457:Peptidoglycan / Q000096:biosynthesis; D010458:Peptidyl Transferases / Q000378:metabolism; D013296:Streptococcus pneumoniae / Q000378:metabolism; D020798:Two-Hybrid System Techniques
D001426:Bacterial Proteins; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; C104636:DivIVA protein, bacteria; D008565:Membrane Proteins; D046915:Penicillin-Binding Proteins; D010406:Penicillins; D010457:Peptidoglycan; D019881:Aminoacyltransferases; D010458:Peptidyl Transferases