Final Exam Question The genome of the Streptococcus pneumoniae strain Fredrica is studying includes the following features that she needs to highlight in a simple diagram i several important chromosomal genes including pspA a gene encoding pneumococcal surface protein A plyA a gene encoding the S pneumoniae pneumolysin an operon including ptsA ptsB ptsC ptsD encoding the components of a phosphotransferase transport system that can transport glucose into the cytoplasm a gene encoding lactate dehydrogenase ldh and genes for each of the glycolytic enzymes blaA a secreted protein that can enzymatically inactivate lactam antibiotics encodes Ampicillin resistance a lac operon lacZ lacY lacA encoding proteins very similar to their counterparts in E coli ii a plasmid that carries pilA a gene encoding the major protein of the pilus that mediates attachment to epithelial cells in the lungs and middle ear pilZ A gene encoding the adhesin for the PilA pilus Several genes NOT PRESENT in the S pneumoniae genome include those encoding TCA cycle enzymes those encoding electron transport chain proteins 1 Be able to draw a single labeled diagram of S pneumoniae that depicts this organism and the location of each of the features specified below a Functional anatomy of S pneumoniae the shape of the organism the layers of the cell envelope including the capsule Do label the layers do NOT draw individual lipid molecules do clearly indicate whether this is a Gram positive bacterium the location of the attachment pilus b Genetic anatomy of S pneumoniae Depict the location of pspA and blaA in your cell diagram pspA is a gene encoding pneumococcal surface protein A These would be located around the diagram such as where the M protein on the surface Since pspA is a gene shouldn t it be in the nucleoid region Nope it s on the surface Also this part is referring to the genetic anatomy blaA is a secreted protein that uses enzymes to inactivate lactam antibiotics These proteins would be located inside the cytoplasm with enzymes around them These can depicted using dots see page 543 of our textbook to see the diagram I am referring to blaA and pspA are gene that code for the proteins not the protein itself They should be located in the genome So they would just be in the dark yellow swirly part Yes it says that they are on a chromosomal gene in the background information c Biochemical anatomy of S pneumoniae show on your diagram where you would expect to find Teichoic acids Pneumolysin galactosidase LacZ PspA bacteria use this to bind to surfaces for colonization glue lactamase BlaA PtsABCD a multiprotein complex PilZ I think beta lactamase is secreted by the cell The teichoic acid is found on the Peptidoglycan layer in the cell wall It goes up to the outer cell surface Pneumolysin is an endotoxin secreted by the microbe It can lyse and interfere with the function of cells and soluble molecules of the immune system galactosidase is an enzyme found in the cytoplasm of Lac microbes PspA is a surface protein PspA is a GENE that encodes for a protein It s not the protein So would it be in nucleoid region Actually it s on the peptidoglycan layer surface h In the review Dr Stein said to realize when he is referring to PspA capital which is the protein lactamase would be found in the cytoplasm if it has the resistance to beta lactam Since PilZ is a gene encoding the adhesin of the PilA pilus it would be located at the end of the attachment pilli It would stick to the cytoplasmic membrane and then the pili could form The multiprotein complex would be proteins that are found on the cytoplasmic membrane the squiggly thing in the diagram above B lactamase is secreted by Gram bacteria The b lactamases of gram positive species are largely extracellular although depending on the growth conditions some enzyme may adhere to the cytoplasmic S pneumoniae is resistant against beta lactams by changing the target that the beta lactam binds to http www ncbi nlm nih gov pmc articles PMC105050 pdf jm002359 pdf tool pmcentrez This source seems to say that beta galactose in S pneumoniae is found on the cell wall http www ncbi nlm nih gov pmc articles PMC2681812 pdf 1601 08 pdf tool pmcentrez Yep I think since it s not italicized it s referring to the protein itself http mmbr asm org cgi content full 65 2 187 2 Fredrica realizes that Bill Gates may not understand the genetic nomenclature contained within her drawing of the cell so she decides that it would be helpful to prepare an additional figure that would explain the concept of a gene She decides that her drawing should highlight the ptsABCD gene operon Prepare a simple figure that shows how information is converted from a DNA molecule to a protein Include in your figure the correct location of 5 and 3 ends of each molecule the location of transcriptional start and stop sites any promoters ribosome binding sites start and stop codons amino and carboxy termini of the protein and site of operon regulation amino would be the 5 of the protein and carboxy termini would be the 3 of the protein True The Transcriptional start site actually comes AFTER the operator I think there should be four different polypeptide strands that are translated they combine later in the protein structure This is correct one for each gene So exactly how would the diagram look if correct In addition to the transcription start site being past the operator there would be 4 different proteins created So 3 more protein drawings and each of them would have an amino and carboxy terminus Would the mRNA part be affected No I think there should just be one mRNA with introns exons that eventually make it into one cohesive protein nick joy There are amino and carboxyl groups between each amino acid connecting them to each other but the amino TERMINUS is only found at the unbound 5 end of the strand carboxy TERMINUS at the unbound 3 end 1 3 Functional components of S pneumonia Virulence Factors Capsule protects S pneumoniae from digestion after endocytosis because it is composed ot chemcials normally found in the body so it tricks the innate immune response into thinking that it is part of you compounded with it s being slippery the capsule prevents phagocytosis blocks compliment binding inhibites digestion after endocytosis andprevents opsonization by antibiotics and protects the bacteria from MAC since the cell membrane is too deep within the capsule for the MAC needle to reach and lyse the cell Attachment PilA Pilus