May serve a regulatory role in expression of downstream gene pssA; in a pssL-pssA-lacZ fusion mutation of the start codon to a stop codon in pssL decreases expression of beta-galactosidase, suggesting translation of the 2 genes is coupled. A fusion of the 5' UTR and initial codons of the gene with lacZ allows expression of beta-galactosidase, suggesting this protein is expressed (at protein level). This gene lies upstream of and overlaps pssA on the same strand in another reading frame.