Active site plasticity enables metal-dependent tuning of Cas5d nuclease activity in CRISPR-Cas type I-C system

Punetha, Ankita; Sivathanu, R.; Anand, B.

doi:10.1093/nar/gkt1335

Cited by 27 publications

(27 citation statements)

References 38 publications

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“…While Cas6 is pervasive among most type I systems, the only exception to this is observed in type I-C, wherein Cas6 is absent and its role is adopted by Cas5, which is shown to be involved in pre-crRNA processing (Garside et al, 2012;Nam et al, 2012;Koo et al, 2013;Punetha et al, 2014) (Fig. 3C).…”

Section: Type I and Type Iii Crispr Systemsmentioning

confidence: 99%

“…3C). Intriguingly, Cas5 in other type I systems appears to be inert and the gain of function with respect to RNA processing is uniquely seen in type I-C. Cas5/I-C processes the pre-CRISPR transcript individually as well as part of the Cascade/I-C complex in a metalindependent fashion (Punetha et al, 2014). Unlike type I-E, Cascade/I-C comprises of only three Cas proteins viz., Cas5, Csd1 and Csd2.…”

Section: Type I and Type Iii Crispr Systemsmentioning

confidence: 99%

“…This parallel processing of the crRNA seems to be an evolutionary adaptation for eliciting a rapid immune response and confers a selective advantage against genome predators. Further, the stoichiometry of the constituents of the RNP complex in type I-C may differ from type I-E as Csd1/I-C seems to be a fusion of its functional homolog Cse1/I-E and Cse2/I-E (Punetha et al, 2014). Apart from the RNase activity, Cas5/I-C and Csd1/I-C also exhibit promiscuous DNase activity that is selectively promoted in the presence of divalent metals (Punetha et al, 2014).…”

Section: Type I and Type Iii Crispr Systemsmentioning

confidence: 99%

“…Further, the stoichiometry of the constituents of the RNP complex in type I-C may differ from type I-E as Csd1/I-C seems to be a fusion of its functional homolog Cse1/I-E and Cse2/I-E (Punetha et al, 2014). Apart from the RNase activity, Cas5/I-C and Csd1/I-C also exhibit promiscuous DNase activity that is selectively promoted in the presence of divalent metals (Punetha et al, 2014). Remarkably, the active site residues in Cas5/I-C show considerable functional overlap in both RNA and DNA hydrolysis (Punetha et al, 2014).…”

Section: Type I and Type Iii Crispr Systemsmentioning

confidence: 99%

“…Apart from the RNase activity, Cas5/I-C and Csd1/I-C also exhibit promiscuous DNase activity that is selectively promoted in the presence of divalent metals (Punetha et al, 2014). Remarkably, the active site residues in Cas5/I-C show considerable functional overlap in both RNA and DNA hydrolysis (Punetha et al, 2014). The mechanism of nucleic acid hydrolysis in type I-C also seems to follow a general acid base catalytic mechanism.…”

Section: Type I and Type Iii Crispr Systemsmentioning

confidence: 99%

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Cutting it Right: Plasticity and Strategy of CRISPR RNA Specific Nucleases

Punetha

Yoganand

Nimkar

et al. 2017

Proceedings of the Indian National Science Academy

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The existence of adaptive immunity in prokaryotes came to light with the discovery of the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) in association with CRISPR-associated (Cas) proteins. This RNA mediated defence system confers resistance against the invading mobile genetic elements such as phages and plasmids. The CRISPR-Cas system operates by forming a ribonucleoprotein complex that comprises of an invader derived small RNA and Cas protein(s). Herein the small RNA acts as a guide to recognize the nucleic acid target whereas the Cas proteins facilitate target annihilation. Given the cardinal role adopted by this small RNA, its maturation from the pre-CRISPR transcript forms a pivot for successful adaptive immunity. The mandate to generate the guide CRISPR RNA (crRNA) is fulfilled by specific endoribonuclease, which processes the pre-crRNA transcript in between the repeats to liberate the individual interfering units. Intriguingly, while some endoRNases of the CRISPR system are able to process the pre-crRNA independently, others require participation of additional Cas proteins, which form a multi-protein complex for processing the pre-crRNA. Additionally, some CRISPR variants require non-Cas auxiliary factors to process the pre-crRNA. The mode of crRNA maturation further diversifies as the endoRNases in CRISPR variants coevolve with repeat clusters that exhibit high diversity in sequence and folding. Therefore, the maturation of a specific crRNA requires a distinct mechanistic solution for substrate discrimination by these endoRNases, the understanding of which is essential for appreciating the CRISPR biology. This review highlights the vivid modes adopted by the diverse CRISPR-Cas systems to generate the mature crRNA. Keywords: CRISPR RNA; CRISPR-Cas IntroductionIn order to survive, all organisms must overcome their predators. The prokaryotes and their viral predators coexist in natural and man-made environment and therefore the prokaryotes face a constant threat of getting infected by phages. This results in acute pressure on the microbial community to coevolve with their predators causing an evolutionary arms race between prey and predator. Pitted against a hostile environment, prokaryotes have developed multilayered antiviral defense systems, which act at various stages of the infection cycle of the invader. These include various innate defense systems like surface exclusion (receptor downregulation or masking), super infection exclusion (Sie systems), restrictionmodification systems (R-M and R-M like systems), and abortive infection systems (Abi) (Hyman and Abedon, 2010; Labrie et al., 2010;Westra et al., 2012a). These innate defense mechanisms are diffusive in nature and do not rely on the identity of the predator to elicit a response (Fig 1). Added to this repertoire of arsenals, the recently discovered Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR) in association with CRISPRassociated (Cas) proteins endows the bacteria and archaea with an adaptive immunity (Ja...

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Section: Type I and Type Iii Crispr Systemsmentioning

confidence: 99%

Section: Type I and Type Iii Crispr Systemsmentioning

confidence: 99%

Section: Type I and Type Iii Crispr Systemsmentioning

confidence: 99%

Section: Type I and Type Iii Crispr Systemsmentioning

confidence: 99%

Section: Type I and Type Iii Crispr Systemsmentioning

confidence: 99%

See 3 more Smart Citations

Cutting it Right: Plasticity and Strategy of CRISPR RNA Specific Nucleases

Punetha

Yoganand

Nimkar

et al. 2017

Proceedings of the Indian National Science Academy

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Dual nuclease activity of a Cas2 protein in CRISPR–Cas subtype I‐B of Leptospira interrogans

et al. 2016

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Edited by Renee TsolisLeptospira interrogans serovar Copenhageni strain Fiocruz L1-130 carries a set of cas genes associated with CRISPR-Cas subtype I-B. Herein, we report for the first time active transcription of a set of cas genes (cas1 to cas8) of L. interrogans where cas4, cas1, cas2 and cas6, cas3, cas8, cas7, cas5 are clustered together in two independent operons. As an initial step toward comprehensive understanding of CRISPR-Cas system in spirochete, the biochemical study of one of the core Leptospira Cas2 proteins (Lep_Cas2) showed nuclease activity on both DNA and RNA in a nonspecific manner. Additionally, unlike other known Cas2 proteins, Lep_Cas2 showed metal-independent RNase activity and preferential activity on RNA over DNA. These results provide insight for understanding Cas2 diversity existing in the prokaryotic adaptive immune system.

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