RESUMEN
DNA modifications vary in form and function but generally do not alter Watson-Crick base pairing. Diaminopurine (Z) is an exception because it completely replaces adenine and forms three hydrogen bonds with thymine in cyanophage S-2L genomic DNA. However, the biosynthesis, prevalence, and importance of Z genomes remain unexplored. Here, we report a multienzyme system that supports Z-genome synthesis. We identified dozens of globally widespread phages harboring such enzymes, and we further verified the Z genome in one of these phages, Acinetobacter phage SH-Ab 15497, by using liquid chromatography with ultraviolet and mass spectrometry. The Z genome endows phages with evolutionary advantages for evading the attack of host restriction enzymes, and the characterization of its biosynthetic pathway enables Z-DNA production on a large scale for a diverse range of applications.
Asunto(s)
2-Aminopurina/metabolismo , Adenilosuccinato Sintasa/química , Bacteriófagos/química , Bacteriófagos/enzimología , ADN Viral/química , ADN de Forma Z/química , Proteínas no Estructurales Virales/química , 2-Aminopurina/química , Adenilosuccinato Liasa/química , Adenilosuccinato Liasa/genética , Adenilosuccinato Liasa/metabolismo , Adenilosuccinato Sintasa/genética , Adenilosuccinato Sintasa/metabolismo , Bacteriófagos/genética , Emparejamiento Base , Vías Biosintéticas , ADN Viral/biosíntesis , ADN Viral/genética , ADN de Forma Z/biosíntesis , ADN de Forma Z/genética , Genoma Viral , Enlace de Hidrógeno , Dominios Proteicos , Especificidad por Sustrato , Timina/química , Timina/metabolismo , Proteínas no Estructurales Virales/genética , Proteínas no Estructurales Virales/metabolismoRESUMEN
The Agrobacterium-mediated transformation system is the most commonly used method in soybean transformation. Screening of soybean genotypes favorable for Agrobacterium-infection and tissue regeneration is the most important step to establish an efficient genetic transformation system. In this study, twenty soybean genotypes that originated from different soybean production regions in China were screened for transient infection, regeneration capacity, and stable transgenic efficiency. Three genotypes, Yuechun 04-5, Yuechun 03-3, and Tianlong 1, showed comparable stable transgenic efficiencies with that of the previously reported American genotypes Williams 82 and Jack in our experimental system. For the Tianlong 1, the average stable transformation efficiency is 4.59%, higher than that of control genotypes (Jack and Williams 82), which is enough for further genomic research and genetic engineering. While polymerase chain reaction (PCR), LibertyLink strips, and ß-glucuronidase (GUS) staining assays were used to detect the insertion and expression of the transgene, leaves painted with 135 mg/L Basta could efficiently identify the transformants.