RESUMO
Bacterial integration host factors (IHFs) play central roles in the cellular processes of recombination, DNA replication, transcription, and bacterial pathogenesis. We describe here a novel mycobacterial IHF (mIHF) of Mycobacterium smegmatis and Mycobacterium tuberculosis that stimulates integration of mycobacteriophage L5. mIHF is the product of a single gene and is unrelated at the sequence level to other integration host factors. By itself, mIHF does not bind preferentially to attP DNA, although it significantly alters the pattern of integrase (Int) binding, promoting the formation of specific integrase-mIHF-attP intasome complexes.
Assuntos
Proteínas de Bactérias/biossíntese , Mycobacterium tuberculosis/virologia , Mycobacterium/virologia , Sequência de Aminoácidos , Proteínas de Bactérias/química , Proteínas de Bactérias/isolamento & purificação , Sequência de Bases , Pegada de DNA , Proteínas de Ligação a DNA/biossíntese , Desoxirribonuclease I , Genes Virais , Fatores Hospedeiros de Integração , Dados de Sequência Molecular , Micobacteriófagos/genética , Micobacteriófagos/fisiologia , Recombinação Genética , Homologia de Sequência de AminoácidosRESUMO
Prenylated proteins, labeled in the isoprenoid residue by growing CHO cells in medium containing [5-3H]mevalonate, were degraded by three different proteolytic procedures, enzymatic or alkaline hydrolysis as well as hydrazinolysis. The products thus obtained were analyzed by HPLC with chemically prepared all-trans-geranylgeranylcysteine as a standard. About 10% of the radioactive products released by each lytic procedure showed the same chromatographic properties as geranylgeranylcysteine. This verifies the earlier conclusion, based on less-direct evidence, that this thioether derivative of cysteine is a component of naturally occurring proteins. The finding of this modified amino acid as a product of hydrazinolysis indicates that it is a carboxyl-terminal amino acid and that it is not carboxyl-methylated.
