Structural organization of human cytomegalovirus DNA

Area of Science:

• Molecular Biology
• Virology
• Genetics

Background:

• Human Cytomegalovirus (HCMV) is a significant human pathogen.
• Understanding the structure of HCMV DNA is crucial for studying viral replication and pathogenesis.
• Previous studies have indicated heterogeneity in HCMV DNA preparations.

Purpose of the Study:

• To characterize the molecular weight and sequence complexity of HCMV DNA molecules.
• To investigate the relationship between different size classes of HCMV DNA.
• To identify structural features within the HCMV genome, such as inversions.

Main Methods:

• Sedimentation analysis to determine molecular weight.
• Buoyant density centrifugation for purity assessment.
• Restriction enzyme cleavage to analyze DNA fragments.
• Partial denaturation mapping to compare DNA sequences.

Main Results:

• HCMV DNA preparations contain two primary molecular weight size classes: 150-155 x 10^6 and 100 x 10^6 daltons.
• Both size classes share identical sequences, with the larger molecules encompassing the complete set found in smaller molecules.
• The complete HCMV genome (150-155 x 10^6 daltons) appears to consist of two regions that can undergo complete inversions relative to each other.

Conclusions:

• HCMV DNA exhibits size heterogeneity attributed to sequence content and potential genomic inversions.
• The larger HCMV DNA molecules represent the full genome, while smaller molecules contain variable subsets of these sequences.
• These findings provide insights into the structural organization and variability of the HCMV genome.