The adenine-thymine domain of the simian virus 40 core origin directs DNA bending and coordinately regulates DNA replication.

AUTOR(ES)

Deb, S

RESUMO

The simian virus 40 origin of replication contains a 20-base-pair adenine-thymine-rich segment with the sequence 5'-TGCATAAATAAAAAAAATTA-3'. The continuous tract of eight adenines is highly conserved among polyomaviruses. We used single-base substitutions to map structural and functional features of this DNA. Mutations in the AAA and AAAAAAAATT sequences significantly reduce DNA replication and thus identify two sequence-specific functional domains or a single domain with two parts. The AAAAAAAATT sequence also determines a DNA conformation that is characteristic of DNA bending. Single-base mutations in this domain change the degree of net bending, presumably by altering the length and location of the bending sequence. Thus, DNA bending in the correct conformation and location may be a structural signal for replication in polyomavirus origins and perhaps in other origins of replication with consecutive runs of adenines. The first five base pairs (TGCAT) of the 20-base-pair segment and the T between the AAA and AAAAAAAATT domains serve a sequence-independent function that may establish proper spacing within the core origin.

Documentos Relacionados

• DNA bending by an adenine–thymine tract and its role in gene regulation
• Domain structure of the simian virus 40 core origin of replication.
• The T-antigen-binding domain of the simian virus 40 core origin of replication.
• The Raman spectra of left-handed DNA oligomers incorporating adenine-thymine base pairs+.
• Spacing is crucial for coordination of domain functions within the simian virus 40 core origin of replication.