| Id |
Subject |
Object |
Predicate |
Lexical cue |
| TextSentencer_T1 |
0-38 |
Sentence |
denotes |
From SARS and MERS CoVs to SARS-CoV-2: |
| TextSentencer_T2 |
39-121 |
Sentence |
denotes |
Moving toward more biased codon usage in viral structural and nonstructural genes. |
| TextSentencer_T3 |
122-133 |
Sentence |
denotes |
BACKGROUND: |
| TextSentencer_T4 |
134-238 |
Sentence |
denotes |
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emerging disease with fatal outcomes. |
| TextSentencer_T5 |
239-537 |
Sentence |
denotes |
In this study, a fundamental knowledge gap question is to be resolved by evaluating the differences in biological and pathogenic aspects of SARS-CoV-2 and the changes in SARS-CoV-2 in comparison with the two prior major COV epidemics, SARS and Middle East respiratory syndrome (MERS) coronaviruses. |
| TextSentencer_T6 |
538-546 |
Sentence |
denotes |
METHODS: |
| TextSentencer_T7 |
547-980 |
Sentence |
denotes |
The genome composition, nucleotide analysis, codon usage indices, relative synonymous codons usage, and effective number of codons (ENc) were analyzed in the four structural genes; Spike (S), Envelope (E), membrane (M), and Nucleocapsid (N) genes, and two of the most important nonstructural genes comprising RNA-dependent RNA polymerase and main protease (Mpro) of SARS-CoV-2, Beta-CoV from pangolins, bat SARS, MERS, and SARS CoVs. |
| TextSentencer_T8 |
981-1043 |
Sentence |
denotes |
RESULTS: SARS-CoV-2 prefers pyrimidine rich codons to purines. |
| TextSentencer_T9 |
1044-1160 |
Sentence |
denotes |
Most high-frequency codons were ending with A or T, while the low frequency and rare codons were ending with G or C. |
| TextSentencer_T10 |
1161-1269 |
Sentence |
denotes |
SARS-CoV-2 structural proteins showed 5 to 20 lower ENc values, compared with SARS, bat SARS, and MERS CoVs. |
| TextSentencer_T11 |
1270-1373 |
Sentence |
denotes |
This implies higher codon bias and higher gene expression efficiency of SARS-CoV-2 structural proteins. |
| TextSentencer_T12 |
1374-1456 |
Sentence |
denotes |
SARS-CoV-2 encoded the highest number of over-biased and negatively biased codons. |
| TextSentencer_T13 |
1457-1572 |
Sentence |
denotes |
Pangolin Beta-CoV showed little differences with SARS-CoV-2 ENc values, compared with SARS, bat SARS, and MERS CoV. |
| TextSentencer_T14 |
1573-1584 |
Sentence |
denotes |
CONCLUSION: |
| TextSentencer_T15 |
1585-1779 |
Sentence |
denotes |
Extreme bias and lower ENc values of SARS-CoV-2, especially in Spike, Envelope, and Mpro genes, are suggestive for higher gene expression efficiency, compared with SARS, bat SARS, and MERS CoVs. |
