Abstract: Provided herein are isolated polynucleotides encoding collagen-like polypeptide domains and the encoded polypeptides. In one such polypeptide, at least a portion of the encoded collagen-like polypeptide domain is in the form of Gly-X-Y triads, where X and Y symbolize individual amino acids; X is proline in at least 20% of the triads; Y is proline in at least 20% of the triads. The encoding polynucleotide of such a polypeptide encodes a region having at least 50 consecutive amino acids, wherein the region is at least 90% identical to an amino acid sequence of a naturally occurring collagen polypeptide; and no more than 98% of the nucleotides of the collagen-like polypeptide domain-encoding portion of the polynucleotide fall into a window of 100 consecutive nucleotides in which the nucleotides of the window have greater than 98% identity to a naturally occurring collagen-encoding nucleotide sequence.

Abstract: A method and system for synthesizing one or more pieces of DNA with desired sequences using pooled DNA, the method comprising a hierarchical division phase and a hierarchical assembly phase. In the division phase, the sequences of one or more pieces of DNA with desired nucleic acid sequences are recursively: divided into partially overlapping resulting pieces of DNA, and the resulting pieces of DNA assigned to a plurality of pools except after the after the final division step, wherein overlapping, adjacent resulting pieces of DNA are assigned to different pools. In the assembly phase, pools of oligonucleotides are obtained corresponding to the pools of the resulting pieces of DNA, and one or more pieces of DNA with desired sequences are assembled by overlap extension in the reverse order of the hierarchical division. Embodiments of the method combine the advantages of hierarchical assembly with the advantages of pooled oligonucleotides.