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In Vitro and In Vivo Studies of Two Essential MRSA Cell Wall Synthesis Enzymes
In Vitro and In Vivo Studies of Two Essential MRSA Cell Wall Synthesis Enzymes
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20260202103508
- ISBN
- 9798280719774
- DDC
- 576
- 저자명
- Canavan, Clare.
- 서명/저자
- In Vitro and In Vivo Studies of Two Essential MRSA Cell Wall Synthesis Enzymes
- 발행사항
- [Sl] : Harvard University, 2025
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2025
- 형태사항
- 153 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 86-12, Section: B.
- 주기사항
- Advisor: Kahne, Dan;Kruse, Andrew.
- 학위논문주기
- Thesis (Ph.D.)--Harvard University, 2025.
- 초록/해제
- 요약Methicillin resistant Staphylococcus aureus (MRSA) is a growing healthcare threat worldwide. The mechanism of antibiotic resistance in MRSA relies on the acquired cell wall synthesis enzyme PBP2a, which rescues transpeptidase (TP) activity upon inhibition by β-lactam drugs. Previous evidence reveals a functional coordination between PBP2a and PBP2, an essential S. aureus enzyme with glycosyltransferase (GT) and TP activities.Excitingly, recent data have demonstrated that PBP2 and PBP2a form a physical complex, which can be isolated via tandem affinity purification and size exclusion chromatography. In Chapter 2 of this thesis work, we replicate the PBP2/PBP2a complex purification in an effort to further characterize the heterodimer. However, binding assays and structural studies present challenges that suggest a weak binding interaction in vitro.To investigate the coordination between PBP2 and PBP2a within the S. aureus cell, we express PBP2a in a methicillin sensitive Staphylococcus aureus (MSSA) background and study its impact on PBP2 localization. In Chapter 3, we explore PBP2's recruitment to the division site and the relevance of PBP2a for this recruitment under antibiotic treatment. Here, we find that PBP2a can rescue PBP2's septal localization when it is disrupted by β-lactams. We further demonstrate that antibiotic inhibition of either GT or TP activity displaces PBP2 from the division site, but a catalytically inactive copy of PBP2 is still able to localize properly in the presence of other active PBP2 enzymes.Ultimately, our data suggest a unique model of PBP2 septal recruitment, in which nascent septal peptidoglycan recruits PBP2 to the division site in a positive feedback loop, and other divisome components stabilize the enzyme's localization once it arrives. These discoveries add important insights into how S. aureus is positioned for its essential role in cell division and how PBP2a acts to rescue MRSA strains from β-lactam inhibition.
- 일반주제명
- Microbiology
- 일반주제명
- Biochemistry
- 일반주제명
- Cellular biology
- 일반주제명
- Molecular biology
- 키워드
- Enzymes
- 키워드
- Transpeptidases
- 기타저자
- Harvard University Chemical Biology
- 기본자료저록
- Dissertations Abstracts International. 86-12B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■020 ▼a9798280719774
■035 ▼a(MiAaPQ)AAI32003009
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a576
■1001 ▼aCanavan, Clare.▼0(orcid)0000-0003-0648-2373
■24510▼aIn Vitro and In Vivo Studies of Two Essential MRSA Cell Wall Synthesis Enzymes
■260 ▼a[Sl]▼bHarvard University▼c2025
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2025
■300 ▼a153 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 86-12, Section: B.
■500 ▼aAdvisor: Kahne, Dan;Kruse, Andrew.
■5021 ▼aThesis (Ph.D.)--Harvard University, 2025.
■520 ▼aMethicillin resistant Staphylococcus aureus (MRSA) is a growing healthcare threat worldwide. The mechanism of antibiotic resistance in MRSA relies on the acquired cell wall synthesis enzyme PBP2a, which rescues transpeptidase (TP) activity upon inhibition by β-lactam drugs. Previous evidence reveals a functional coordination between PBP2a and PBP2, an essential S. aureus enzyme with glycosyltransferase (GT) and TP activities.Excitingly, recent data have demonstrated that PBP2 and PBP2a form a physical complex, which can be isolated via tandem affinity purification and size exclusion chromatography. In Chapter 2 of this thesis work, we replicate the PBP2/PBP2a complex purification in an effort to further characterize the heterodimer. However, binding assays and structural studies present challenges that suggest a weak binding interaction in vitro.To investigate the coordination between PBP2 and PBP2a within the S. aureus cell, we express PBP2a in a methicillin sensitive Staphylococcus aureus (MSSA) background and study its impact on PBP2 localization. In Chapter 3, we explore PBP2's recruitment to the division site and the relevance of PBP2a for this recruitment under antibiotic treatment. Here, we find that PBP2a can rescue PBP2's septal localization when it is disrupted by β-lactams. We further demonstrate that antibiotic inhibition of either GT or TP activity displaces PBP2 from the division site, but a catalytically inactive copy of PBP2 is still able to localize properly in the presence of other active PBP2 enzymes.Ultimately, our data suggest a unique model of PBP2 septal recruitment, in which nascent septal peptidoglycan recruits PBP2 to the division site in a positive feedback loop, and other divisome components stabilize the enzyme's localization once it arrives. These discoveries add important insights into how S. aureus is positioned for its essential role in cell division and how PBP2a acts to rescue MRSA strains from β-lactam inhibition.
■590 ▼aSchool code: 0084.
■650 4▼aMicrobiology
■650 4▼aBiochemistry
■650 4▼aCellular biology
■650 4▼aMolecular biology
■653 ▼aStaphylococcus aureus
■653 ▼aCell wall synthesis
■653 ▼aEnzymes
■653 ▼aGlycosyltransferases
■653 ▼aTranspeptidases
■690 ▼a0410
■690 ▼a0487
■690 ▼a0379
■690 ▼a0307
■71020▼aHarvard University▼bChemical Biology.
■7730 ▼tDissertations Abstracts International▼g86-12B.
■790 ▼a0084
■791 ▼aPh.D.
■792 ▼a2025
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17357413▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
