Sequence analysis Sequence composition, complexity and repeats true Sequence repeats Protein repeats Sequence_composition_complexity_and_repeats beta12orEarlier Nucleic acid repeats Sequence complexity Sequence composition Protein sequence repeats This includes repetitive elements within a nucleic acid sequence, e.g. long terminal repeats (LTRs); sequences (typically retroviral) directly repeated at both ends of a sequence and other types of repeating unit. Repeat sequences This includes short repetitive subsequences (repeat sequences) in a protein sequence. Low complexity sequences The archival, processing and analysis of the basic character composition of molecular sequences, for example character or word frequency, ambiguity, complexity, particularly regions of low complexity, and repeats or the repetitive nature of molecular sequences.