The present invention relates to the identification of novel serine proteases in Gram-positive microorganisms. The present invention provides the nuclei acid and amino acid sequences for the Bacillus subtilis serine proteases SP1, SP2, SP3, SP4 and SP5. The present invention also provides host cells having a mutation or deletion of part or all of the gene encoding SP1, SP2, SP3, SP4 and SP5. The present invention also provides host cells further comprising nucleic acid encoding desired heterologous proteins such as enzymes. The present invention also provides a cleaning composition comprising a serine protease of the present invention.