The present invention relates to cells that have been genetically manipulated to have an altered capacity to express and/or produce proteins of interest. In particular, the present invention relates to modified host cells of Gram-positive microorganisms, such as Bacillus species that are capable of overexpressing ymaH. The invention encompasses polynucleotide constructs and expression vectors containing polynucleotide sequences that encode YmaH, and the modified host cells comprising them. In particular, the present invention relates to compositions and methods of overexpressing YmaH for enhancing the expression and production of proteins of interest (e.g., proteases) in Bacillus species.