Translate the following mRNA sequence into its amino acid sequence using three-letter and one-letter abbreviations:
CCG CCU CCC

Three-letter abbreviation: Leu-Leu-Leu

One-letter abbreviation: L-L-L

Three-letter abbreviation: Pro-Pro-Pro

One-letter abbreviation: P-P-P

Three-letter abbreviation: Gln-His-His

One-letter abbreviation: Q-H-H

Three-letter abbreviation: Arg-Arg-Arg

One-letter abbreviation: R-R-R