The present invention relates to a type I collagen which comprises a C-terminus and/or N-terminus propeptide, obtainable by expressing in a plant or isolated plant cell a type I collagen alpha chain including a signal peptide for targeting to a vacuole and being devoid of an ER retention sequence, a mammalian lysyl hydroxylase 3 (LH3), and a human prolyl 4 hydroxylase (P4H) including a signal peptide for targeting to a vacuole and being devoid of an ER retention sequence, and accumulating said type I collagen alpha chain, said LH3 and said P4H in a vacuole of the plant or the isolated plant cell. The present invention further relates to a method of producing fibrillar collagen in a plant or an isolated plant cell comprising: (a) targeting to and accumulating in a vacuole of the plant or the isolated plant cell a collagen alpha I chain including a signal peptide for targeting to a vacuole and being devoid of an ER retention sequence, a collagen alpha II chain including a signal peptide for targeting to a vacuole and being devoid of an ER retention sequence, and an exogenous human prolyl 4 hydroxylase (P4H) including a signal peptide for targeting to a vacuole and being devoid of an ER retention sequence, said collagen alpha I chain, said collagen alpha II chain and said human prolyl 4 hydroxylase (P4H) being expressed in said plant or isolated plant cell； and (b) harvesting said plant or plant cell and isolating the collagen.
