1
|
Sudhakar S, Barkau CL, Chilamkurthy R, Barber HM, Pater AA, Moran SD, Damha MJ, Pradeepkumar PI, Gagnon KT. Binding to the conserved and stably folded guide RNA pseudoknot induces Cas12a conformational changes during ribonucleoprotein assembly. J Biol Chem 2023; 299:104700. [PMID: 37059184 PMCID: PMC10200996 DOI: 10.1016/j.jbc.2023.104700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 04/05/2023] [Accepted: 04/07/2023] [Indexed: 04/16/2023] Open
Abstract
Ribonucleoproteins (RNPs) comprise one or more RNA and protein molecules that interact to form a stable complex, which commonly involves conformational changes in the more flexible RNA components. Here, we propose that Cas12a RNP assembly with its cognate CRISPR RNA (crRNA) guide instead proceeds primarily through Cas12a conformational changes during binding to more stable, prefolded crRNA 5' pseudoknot handles. Phylogenetic reconstructions and sequence and structure alignments revealed that the Cas12a proteins are divergent in sequence and structure while the crRNA 5' repeat region, which folds into a pseudoknot and anchors binding to Cas12a, is highly conserved. Molecular dynamics simulations of three Cas12a proteins and their cognate guides revealed substantial flexibility for unbound apo-Cas12a. In contrast, crRNA 5' pseudoknots were predicted to be stable and independently folded. Limited trypsin hydrolysis, differential scanning fluorimetry, thermal denaturation, and CD analyses supported conformational changes of Cas12a during RNP assembly and an independently folded crRNA 5' pseudoknot. This RNP assembly mechanism may be rationalized by evolutionary pressure to conserve CRISPR loci repeat sequence, and therefore guide RNA structure, to maintain function across all phases of the CRISPR defense mechanism.
Collapse
Affiliation(s)
- Sruthi Sudhakar
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, India
| | - Christopher L Barkau
- Department of Biochemistry and Molecular Biology, School of Medicine, Southern Illinois University, Carbondale, Illinois, USA
| | - Ramadevi Chilamkurthy
- Department of Biochemistry and Molecular Biology, School of Medicine, Southern Illinois University, Carbondale, Illinois, USA
| | - Halle M Barber
- Department of Chemistry, McGill University, Montreal, Quebec, Canada
| | - Adrian A Pater
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois, USA
| | - Sean D Moran
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois, USA
| | - Masad J Damha
- Department of Chemistry, McGill University, Montreal, Quebec, Canada
| | - P I Pradeepkumar
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, India.
| | - Keith T Gagnon
- Department of Biochemistry and Molecular Biology, School of Medicine, Southern Illinois University, Carbondale, Illinois, USA; Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois, USA.
| |
Collapse
|
2
|
Jianwei L, Jobichen C, Machida S, Meng S, Read RJ, Hongying C, Jian S, Yuan YA, Sivaraman J. Structures of apo Cas12a and its complex with crRNA and DNA reveal the dynamics of ternary complex formation and target DNA cleavage. PLoS Biol 2023; 21:e3002023. [PMID: 36917574 PMCID: PMC10013913 DOI: 10.1371/journal.pbio.3002023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 02/06/2023] [Indexed: 03/15/2023] Open
Abstract
Cas12a is a programmable nuclease for adaptive immunity against invading nucleic acids in CRISPR-Cas systems. Here, we report the crystal structures of apo Cas12a from Lachnospiraceae bacterium MA2020 (Lb2) and the Lb2Cas12a+crRNA complex, as well as the cryo-EM structure and functional studies of the Lb2Cas12a+crRNA+DNA complex. We demonstrate that apo Lb2Cas12a assumes a unique, elongated conformation, whereas the Lb2Cas12a+crRNA binary complex exhibits a compact conformation that subsequently rearranges to a semi-open conformation in the Lb2Cas12a+crRNA+DNA ternary complex. Notably, in solution, apo Lb2Cas12a is dynamic and can exist in both elongated and compact forms. Residues from Met493 to Leu523 of the WED domain undergo major conformational changes to facilitate the required structural rearrangements. The REC lobe of Lb2Cas12a rotates 103° concomitant with rearrangement of the hinge region close to the WED and RuvC II domains to position the RNA-DNA duplex near the catalytic site. Our findings provide insight into crRNA recognition and the mechanism of target DNA cleavage.
Collapse
Affiliation(s)
- Li Jianwei
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Chacko Jobichen
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Satoru Machida
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Sun Meng
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Randy J. Read
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Chen Hongying
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Shi Jian
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Yuren Adam Yuan
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - J. Sivaraman
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- * E-mail:
| |
Collapse
|
3
|
Behler J, Hess WR. Approaches to study CRISPR RNA biogenesis and the key players involved. Methods 2020; 172:12-26. [PMID: 31325492 DOI: 10.1016/j.ymeth.2019.07.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 05/29/2019] [Accepted: 07/15/2019] [Indexed: 12/26/2022] Open
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) proteins provide an inheritable and adaptive immune system against phages and foreign genetic elements in many bacteria and archaea. The three stages of CRISPR-Cas immunity comprise adaptation, CRISPR RNA (crRNA) biogenesis and interference. The maturation of the pre-crRNA into mature crRNAs, short guide RNAs that target invading nucleic acids, is crucial for the functionality of CRISPR-Cas defense systems. Mature crRNAs assemble with Cas proteins into the ribonucleoprotein (RNP) effector complex and guide the Cas nucleases to the cognate foreign DNA or RNA target. Experimental approaches to characterize these crRNAs, the specific steps toward their maturation and the involved factors, include RNA-seq analyses, enzyme assays, methods such as cryo-electron microscopy, the crystallization of proteins, or UV-induced protein-RNA crosslinking coupled to mass spectrometry analysis. Complex and multiple interactions exist between CRISPR-cas-encoded specific riboendonucleases such as Cas6, Cas5d and Csf5, endonucleases with dual functions in maturation and interference such as the enzymes of the Cas12 and Cas13 families, and nucleases belonging to the cell's degradosome such as RNase E, PNPase and RNase J, both in the maturation as well as in interference. The results of these studies have yielded a picture of unprecedented diversity of sequences, enzymes and biochemical mechanisms.
Collapse
Affiliation(s)
- Juliane Behler
- University of Freiburg, Faculty of Biology, Genetics and Experimental Bioinformatics, Schänzlestr. 1, D-79104 Freiburg, Germany
| | - Wolfgang R Hess
- University of Freiburg, Faculty of Biology, Genetics and Experimental Bioinformatics, Schänzlestr. 1, D-79104 Freiburg, Germany; University of Freiburg, Freiburg Institute for Advanced Studies, Albertstr. 19, D-79104 Freiburg, Germany.
| |
Collapse
|
4
|
Safari F, Zare K, Negahdaripour M, Barekati-Mowahed M, Ghasemi Y. CRISPR Cpf1 proteins: structure, function and implications for genome editing. Cell Biosci 2019; 9:36. [PMID: 31086658 PMCID: PMC6507119 DOI: 10.1186/s13578-019-0298-7] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 04/20/2019] [Indexed: 12/19/2022] Open
Abstract
CRISPR and CRISPR-associated (Cas) protein, as components of microbial adaptive immune system, allows biologists to edit genomic DNA in a precise and specific way. CRISPR-Cas systems are classified into two main classes and six types. Cpf1 is a putative type V (class II) CRISPR effector, which can be programmed with a CRISPR RNA to bind and cleave complementary DNA targets. Cpf1 has recently emerged as an alternative for Cas9, due to its distinct features such as the ability to target T-rich motifs, no need for trans-activating crRNA, inducing a staggered double-strand break and potential for both RNA processing and DNA nuclease activity. In this review, we attempt to discuss the evolutionary origins, basic architectures, and molecular mechanisms of Cpf1 family proteins, as well as crRNA designing and delivery strategies. We will also describe the novel Cpf1 variants, which have broadened the versatility and feasibility of this system in genome editing, transcription regulation, epigenetic modulation, and base editing. Finally, we will be reviewing the recent studies on utilization of Cpf1as a molecular tool for genome editing.
Collapse
Affiliation(s)
- Fatemeh Safari
- Department of Medical Biotechnology, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Khadijeh Zare
- Department of Basic Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Manica Negahdaripour
- Pharmaceutical Sciences Research Center, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mazyar Barekati-Mowahed
- Department of Physiology & Biophysics, School of Medicine, Case Western Reserve University, Ohio, USA
| | - Younes Ghasemi
- Department of Pharmaceutical Biotechnology, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
| |
Collapse
|
5
|
Abstract
Pervasive application of CRISPR-Cas systems in genome editing has prompted an increase in both interest and necessity to further elucidate existing systems as well as discover putative novel systems. The ubiquity and power of current computational platforms have made in silico approaches to CRISPR-Cas identification and characterization accessible to a wider audience and increasingly amenable for processing extensive data sets. Here, we describe in silico methods for predicting and visualizing notable features of CRISPR-Cas systems, including Cas domain determination, CRISPR array visualization, and inference of the protospacer-adjacent motif. The efficiency of these tools enables rapid exploration of CRISPR-Cas diversity across prokaryotic genomes and supports scalable analysis of large genomic data sets.
Collapse
Affiliation(s)
- Matthew A Nethery
- Genomic Sciences Graduate Program, North Carolina State University, Raleigh, NC, United States; Department of Food, Bioprocessing & Nutrition Sciences, North Carolina State University, Raleigh, NC, United States
| | - Rodolphe Barrangou
- Genomic Sciences Graduate Program, North Carolina State University, Raleigh, NC, United States; Department of Food, Bioprocessing & Nutrition Sciences, North Carolina State University, Raleigh, NC, United States.
| |
Collapse
|
6
|
Wang D, Ma D, Han J, Kong L, Li LY, Xi Z. CRISPR RNA Array-Guided Multisite Cleavage for Gene Disruption by Cas9 and Cpf1. Chembiochem 2018; 19:2195-2205. [PMID: 30088313 DOI: 10.1002/cbic.201800241] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Revised: 08/07/2018] [Indexed: 12/19/2022]
Abstract
To achieve multisite-targeting-based DNA cleavage simultaneously, we designed two kinds of CRISPR RNA arrays by fusing four single guide RNAs (sgRNAs for Cas9 or crRNAs for Cpf1) with uncleavable RNA linkers (CRISPRay). The CRISPRay could operate on four adjacent target sites to cleave target DNA in a collaborative manner. Two CRISPR RNA arrays demonstrated robust inactivation of the firefly luciferase gene in living cells. In vitro DNA cleavage and DNA sequencing also verified that sgRNA arrays directed SpCas9 nuclease to cut target DNA at four cleavage sites simultaneously whereas crRNA-array-guided FnCpf1 nuclease showed target-activated, nonspecific DNase activity on both target DNA and nontarget DNA at random sites. Through optimization of the ratio of nuclease and CRIPSR RNAs, CRISPRay should further enhance gene interference in cells. This work presents a simple approach through which to improve multisite-directed gene disruption by fusing four guide RNAs (sgRNAs or crRNAs) into a CRISPR RNA string.
Collapse
Affiliation(s)
- Dan Wang
- Department of Chemical Biology, State Key Laboratory of Elemento-Organic Chemistry, National Pesticide Engineering Research Center, College of Chemistry, Nankai University, Weijin Road 94, Tianjin, 300071, China
| | - Dejun Ma
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, Weijin Road 94, Tianjin, 300071, China
| | - Jingxin Han
- Department of Chemical Biology, State Key Laboratory of Elemento-Organic Chemistry, National Pesticide Engineering Research Center, College of Chemistry, Nankai University, Weijin Road 94, Tianjin, 300071, China
| | - Linghao Kong
- Department of Chemical Biology, State Key Laboratory of Elemento-Organic Chemistry, National Pesticide Engineering Research Center, College of Chemistry, Nankai University, Weijin Road 94, Tianjin, 300071, China
| | - Lu-Yuan Li
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, Weijin Road 94, Tianjin, 300071, China
| | - Zhen Xi
- Department of Chemical Biology, State Key Laboratory of Elemento-Organic Chemistry, National Pesticide Engineering Research Center, College of Chemistry, Nankai University, Weijin Road 94, Tianjin, 300071, China
| |
Collapse
|